The Book of Life was published on July 15, 2014 in hardback, e-book, and audiobook in the US, UK, Canada, and Ireland.
On January 9, 2014, the United States front cover and a two page excerpt were released to the public on USA Today. On May 12, 2014, chapter 1 was released on http://deborahharkness.com, courtesy of Viking and Headline. Chapter 1 was made available to readers in the United Kingdom, Australia, and New Zealand via iTunes.
NOTE: THERE ARE SPOILERS ON THESE PAGES REGARDING THE BOOK OF LIFE.
After traveling through time in Shadow of Night, historian and witch Diana Bishop and vampire scientist Matthew Clairmont return to the present to face new crises and old enemies. At Matthew’s ancestral home at Sept-Tours, they reunite with the cast of characters from A Discovery of Witches—with one significant exception. But the real threat to their future has yet to be revealed, and when it is, the search for Ashmole 782 and its missing pages takes on even more urgency. In the trilogy’s final volume, Harkness deepens her themes of power and passion, family and caring, past deeds and their present consequences. In ancestral homes and university laboratories, using ancient knowledge and modern science, from the hills of the Auvergne to the palaces of Venice and beyond, the couple at last learn what the witches discovered so many centuries ago.
SPOILER ALERT: Click the 'show' button to the right to read a more detailed description of The Book of Life.
The third book in the series opens with the deceased witch Emily Mather and vampire Philippe de Clermont, as ghosts, seeing Matthew and Diana arrive to Sept-Tours. They realize that Diana is pregnant with twins by Matthew. When Emily says that Diana has never liked change, Philippe responds it's because Diana is afraid of what she must become.
Just before greeting Diana and Matthew upon their return to Sept-Tours, vampire Marcus Whitmore remembers how Diana's beloved aunt Emily Mather died while Diana was away. Emily was at the temple dedicated to the goddess near Sept-Tours, as well as vampire Gerbert of Aurillac and witch Peter Knox. Marcus' human fiancee, Phoebe Taylor, joins Marcus before they go out to greet Diana and Matthew. Phoebe is iron-willed and diplomatic.
At the same time at Sept-Tours, vampire Fernando Gonçalves cooks a tortilla española while talking with vampire Gallowglass about how Gallowglass saw Emily die. Peter Knox was touching Emily's head, then, when Emily's partner, Sarah, arrived and shouted her name, Knox released Emily, who crumpled to the ground unconscious and could not be revived. Fernando is the mate of the deceased vampire Hugh de Clermont, who was Gallowglass' father. Gallowglass reveals that Philippe adopted Diana as a daughter with a blood vow. They see Diana's familiar, a firedrake named Corra.
Sarah tells Diana the story of how Emily died, that Emily was using dangerous, higher magics to seek information from spirits about death and disaster that Emily was foreseeing. Knox was trying to read Emily's thoughts but Emily died saying that she knew the secret of the book known as Ashmole 782 and that he would never possess it. Knox threatened investigation into breaches of the covenant, one purpose of which is to hide creatures from coming to the attention of humans. The nine-member Congregation is responsible for enforcing the covenant.
Matthew takes care of Diana while she grieves, and Fernando looks after Sarah. Matthew and Gallowglass discuss that Diana's magical power has increased in the past months. Meanwhile, the ghosts of the deceased Emily and Philippe are joined by the ghost of witch Rebecca Bishop, Diana's deceased mother.
Matthew walks around the grounds of Sept-Tours trying to keep his blood rage sickness under control. He then sees Gallowglass trying to keep Corra from damaging things accidentally. Matthew tells his friend, a daemon called Hamish, that Marcus has a mating bond with Phoebe. Hamish says that Marcus has done a great job as grand master of the Knights of Lazarus while Matthew was away with Diana. Marcus demanded the Congregation punish Knox and that the covenant be revoked. Matthew says that in order to protect the family from the Congregation, the head of the de Clermont family, his older brother Baldwin, forbade Matthew from seeking vengeance against Gerbert and Knox when they earlier facilitated a Congregation witch's torture and interrogation of Diana.
Matthew meets Phoebe, sees her lie politely and convincingly, deciding that she would be a useful addition to the family. Fernando comforts and advises Matthew about the difficulties Matthew will face allowing Diana her freedom, despite Matthew's blood rage compulsions to remain close to Diana. Fernando encourages Matthew to tell Marcus and Hamish about Matthew's blood rage sickness. Matthew feels peaceful when he returns to sleeping Diana. He reflects that he always wanted a wife and children. He makes love with her, wanting the feeling of her safety and their intimacy to last forever. Thinking of how Emily died while Diana was away, Diana asks Matthew to never leave her without saying good-bye. He promises to never leave her.
Baldwin challenges Diana's status as Philippe's adopted daughter. One of Philippe's vampire daughters is asked to formally recognize Diana as a de Clermont. Diana meets Fernando. Gallowglass confirms that Philippe adopted Diana. Diana finds out that Philippe used Matthew as the family's assassin, taking advantage of the strength of Matthew's blood rage. Diana finds out that Gallowglass discreetly watched after her since she was a child.
Philippe's former squire, vampire Alain Le Merle, brings Diana her possessions kept safe since the 1590s: her spell box, other special valuables, and a golden arrowhead on a long chain. He also gives her Philippe's letter that contains evidence that Philippe freely chose to make Diana his adopted daughter. The letter contains a coin, to be returned by Diana in person to the ferryman of the dead in the afterlife, and says to tell Matthew that Philippe would see Diana safe on the other side. The letter also reveals that somehow, Diana was able to keep Philippe company and be of comfort to him after Philippe was rescued from Nazi torture that severely injured him.
Diana meets Verin's husband, a human called Ernst Neumann. Baldwin and Marcus argue about Marcus' efforts to have the Congregation repeal the covenant. It is revealed that Baldwin is the de Clermont vampire member of the Congregation, and that the Congregation censured Knox and barred him from serving as a member of the Congregation because of Knox' role in Emily's death by heart attack. Knox claimed that Matthew has or had Ashmole 782, known as The Book of Life or the book of origins. The book is made from creature parts and may contain their DNA.
The Congregation will go to inspect Sept-Tours, so the daemons and witches must leave there. Ysabeau must go for a while to Gerbert's house as a hostage to ensure the de Clermont's good behavior. Diana tells Matthew that the top priority should be obtaining Ashmole 782 and its missing pages that Edward Kelley removed in 1591. Matthew tells Diana that it will be safest if he obeys Baldwin's orders. Diana remembers that Philippe had told her to "think and stay alive."
Marcus discovers the old family pedigrees, that his vampire father, Matthew, has a disowned vampire son, Benjamin, and that Matthew and Benjamin have blood rage sickness. Marcus is only a carrier. Matthew reveals that Benjamin had tried to betray the family's secrets. Marcus finds out that if Matthew branches off from the de Clermonts as a scion, they can get out from under Baldwin's control as head of the de Clermonts, but Matthew is skeptical. Baldwin would need to be willing to agree to it. Blood rage must be kept secret so the Congregation will not try to destroy those vampires and their families. The Congregation fears blood rage is back, because of recent, gory vampire murders.
Matthew finds out that there was a vampire-witch baby a long time ago and believes it would be useful to find out more about why some vampires and witches can have children together, like Matthew and Diana can.
At Baldwin's request, Diana organizes a formal dinner for the household before Matthew, Diana, Sarah, Fernando, and others leave Sept-Tours. Diana believes Matthew forming a scion is a good idea and they discuss it. At the family dinner, Matthew toasts lost loved ones. Marcus announces that Phoebe will marry him and become a vampire. Miriam's phone number shows up on Matthew's phone, but it's his son Benjamin on the line. Benjamin says he wants Matthew's attention but Matthew knows that Benjamin is seeking something in particular. Baldwin tells Matthew to take care of the Benjamin problem. Diana announces that she is going to the Bishop house in Madison, New York, to try to find information Emily or Diana's mother may have earlier discovered, possibly about The Book of Life.
Diana starts using her magical weaver skills to create new spells while at the Bishop house. Matthew is replacing fence posts outside for some peace of mind but he is thinking about Benjamin. Sarah is grieving for Emily now that she has returned home to where they lived together. Diana meets up with some witches at the store, who later visit and offer to help with some of Diana's and Matthew's problems. Diana realizes that she has discovered a new wish to belong to a community. Fernando encourages Matthew to focus on his scientific studies of blood rage and of The Book of Life. Matthew tells him that he doesn't want Diana to become a vampire because he loves all that she currently is, even though he doesn't want to lose her. Diana saves a child witch from the hot fireplace at the Bishop house and afterwards discovers that her weaver's cords are now part of her hands and wrists. Diana reveals to Sarah and the other witches at the house that Diana is a weaver and has a familiar, the firedrake Corra. Diana and Sarah discuss that dark magic isn't necessarily evil, and that nothing is more powerful than knowledge. Diana finds out that her mother, Rebecca, had been particularly skillful in higher magics.
Diana reveals to Matthew that she earlier gave the goddess the use of Diana's life in exchange for having saved Matthew from death. Diana feels the twins she is carrying move in her. The Bishop house gives Diana her mother's personal spellbook for higher magics, which also contains Diana's caul, a powerful magical object. Diana's friend, a Yale research scientist, Chris Roberts, comes to the Bishop house. He is told about the world of creatures, and their problems, and agrees to study blood rage, creatures' genomes, and The Book of Life questions. Miriam calls and lets them know at the Bishop house that Benjamin has captured a witch, is raping her, and trying to make her bear a vampire-witch child for him. Someone has complained to the Congregation about covenant violations in Madison County of witches associating with vampires. Chris Roberts points out that creature segregation is not the answer, any more than racial segregation was. He says that it's usually about concerns of racial purity. He thinks the existence of creatures will not be able to be kept secret from humans much longer.
Chris Roberts, Diana and Matthew go to New Haven, Connecticut. Diana hears the carillon at Harkness Tower. Diana and Matthew go to Chris Roberts' Yale lab, which has graduate students who have signed nondisclosure agreements. Diana tells Matthew that students want their professors' attention, honesty and faith in them. Matthew tells the graduate students that for scientists, the "whys come after the whats." Miriam Shephard arrives and starts her role as the lab manager. Lucy Merriweather at the Beinecke Library helps Diana research the location of the missing pages from Ashmole 782, The Book of Life. Diana realizes her purpose as a historian is to rediscover forgotten truths. Diana finds out that Peter Knox has recently been seeking the location of Ashmole 782 as well. Lucy goes with Diana to the lab, where they have discovered that the page they have from Ashmole 782 weighs much more than a regular page, and that Ashmole 782 is a magical container that could contain much more than they imagined. Surprising Diana, her adopted son shows up, Jack Blackfriars from the 1590s, having been turned into a vampire by Andrew Hubbard to prevent him from dying from the plague. Jack Blackfriars turns out to have blood rage, and needs Matthew to teach him how better to control it. It also turns out that Matthew's son Benjamin is the vampire who had turned Andrew Hubbard into a vampire. Diana and Matthew's adopted daughter, Annie, from the 1590s died from the plague before Andrew Hubbard could help her. Benjamin had been exploiting Jack's blood rage to make him a killer, trying to get him to turn humans into vampires. Andrew Hubbard has one of the missing Ashmole 782 pages that Jack had been keeping safe for Matthew and Diana, who receive the page. Andrew Hubbard reveals that Benjamin is looking for The Book of Life.
Matthew goes to help Jack with his blood rage while Jack is living at Gallowglass' condo in New Haven, Connecticut. Chris Roberts tells Matthew that he took blood samples from Jack and that he has discovered that blood rage cannot be cured. Baldwin shows up and accesses Jack's memories via his blood. Diana then arrives and uses her magical power to restrain Baldwin. Everyone leaves the condo except Baldwin and Matthew. Baldwin tells Matthew to kill Jack, for his blood rage and because he was the vampire murderer who had been in the news. Matthew goes home and takes Diana to a mountain park where they see the moon. It is Mabon, one year from when they first met. Matthew tells Diana that prevention and symptom reduction of the blood rage might be possible, but not a cure. Diana urges Matthew to form a scion, a separate branch of the de Clermont family to protect Jack, and their other close relatives from other vampires and the Congregation. Matthew says that vampires believe in law, honor and justice. Matthew agrees to try to obtain the support of the other close relatives to form his own scion, while Diana stays safely away from him, looking for the missing page from Ashmole 782. Their separation would be incredibly difficult for both of them.
Gallowglass flies with Diana to Europe. He tells Diana that Phoebe is OK, that she has a strong spine and a stout heart, just like Diana. Diana discovers tattoos on Gallowglass's arm showing that Gallowglass is in love with Diana. They agree that Diana and Matthew are soulmates however. Ysabeau persuades Gerbert it's OK for her to leave imprisonment in Gerbert's home. Gerbert had been focusing on social media and surfing the Internet to the extent of not noticing Ysabeau's covert activities while at his house.
Diana, Sarah and Diana's close friends and family members go to stay at the London house that Matthew gave Diana. Diana stays in a room designed by Matthew to look like a forest at night under the stars and moon, with magical imagery. Phoebe tells Diana she will resign from Sotheby's in preparation to become a vampire. Ysabeau starts to teach Diana how to help lead a branch of a vampire family, called a scion. Ysabeau tells Diana that the Congregation will try to kill Matthew, Jack and anyone else with blood rage once that information is discovered. After a long sleep, Diana examines the Kircher books that she requested be obtained so she can try to find the Ashmole 782 page that has a Tree of Life image on it, before anyone else can find it. Ysabeau obtains the name T.J. Weston as the owner of the Tree of Life image and Phoebe obtains many possible addresses for that person, mostly in South England. Fernando joins Matthew's scion. Sarah brings Diana to the Blackfriars in London where they meet witch Linda Crosby. Diana remembers being happy with Matthew at the Blackfriars in 1591. Sarah tells her that somehow she has to figure out how to be happy in the present, by being herself, not pretending to be otherwise, doing what she needs to do, and keeping her family together. Diana and the others try to determine where she can use magic to determine the location of T.J. Weston. Ysabeau suggests the upstairs ballroom that has Trojan War frescoes that she doesn't like. Diana visits Linda Crosby's coven meeting place and discovers that the coven has remembered her as a powerful witch from her visit in the 1590s, and weaver Ursula Shipton's prophecy that a weaver would come along who would bring hope, rebirth and change, a new golden age for creatures. Using her compendium, Corra's help, and a locator spell, Diana finds out that Chipping Weston is where T.J. Weston and The Book of Life page may be.
Diana and others go to the Old Lodge. Amira senses the blood and fear in the Ashmole 782 pages that Diana has brought, one of which was made from a witch's skin. She says that the witch cursed the book when other witches killed her husband, before the witches killed her. When Diana and others go to Chipping Weston, they find T.J. Weston, who turns out to be the daemon Timothy who Diana had met at the Bodleian Library. He has the Tree of Life page that was made from his grandfather's skin. As long as Diana promises to remember his grandfather, Timothy says he will give her the page. He says that Diana is the one who will learn how it all began, blood, death and fear, and that she is the one who will put a stop to it. Diana and the others make some plans how to obtain The Book of Life from the Bodleian. The goddess comes to Diana and adds an arrow to Diana's body as a weapon for her to use. At the Bodleian, Benjamin takes Phoebe hostage, threatens Diana and the twins with whom she is pregnant, and is stopped by Ysabeau. Diana feels guilty that she was too afraid to use magic to stop him. Ysabeau calls Baldwin. Diana is put on bed rest. Gallowglass chooses not to tell Matthew about what happened.
Matthew is in New Orleans persuading and threatening Marcus' vampire children so they will join Matthew's new scion branch of the family. To obtain Ransome Fayrweather's pledge, Matthew has to recite the names of Ransome's relatives and other vampires that Matthew killed in New Orleans, some of whom were killed to protect the family from the vampires' blood rage being discovered by the Congregation. Fernando arrives and tells Matthew he has joined his scion. He encourages Matthew and Jack Blackfriars to make decorative cradles for the twins, which is a healing activity for them. Chris Roberts arrives and tells Matthew that it appears that blood rage can't be cured because it is a heredity genetic condition. Fernando tells Jack to remember that if you truly love someone, you will cherish what they despise most about themselves.
Fernando tells Matthew what happened with Diana, and Matthew returns to her. They spend time together, reconnecting emotionally and telling each other about what happened to each of them during their time apart. Matthew tells her that she doesn't need to blame herself for not killing Benjamin. Jack and Matthew present to Diana the cradles they made out of rowan wood. Matthew tells Diana he had figured out that Gallowglass was in love with Diana. They both hope Gallowglass finds his mate. Matthew and Marcus discuss Matthew's Bishop-Clairmont scion or clan. They all find out that the witch Benjamin captured has died, as well as Benjamin's child that she was carrying. Diana realizes that Benjamin will be coming for her next, and her water breaks. While she is laboring, Matthew tells her that to every question he ever had or will have, she is the answer. The twins are born healthy, first Rebecca and then Philip, named after grandparents. Baldwin tells Matthew that someone must be watching because the Congregation somehow already knows about the births. Benjamin calls Matthew to show that he knows too. Diana determines that Rebecca needs to consume blood in addition to milk, for the vampire part of her. Verin and Baldwin arrange for Diana to be confirmed as a de Clermont in the Congregation's records. Ysabeau gives Diana and Matthew a grand house in Limousin called Les Revenants, so they can spend time with the twins there as a family. They look in Philippe's personal papers for information about the early days of the Congregation, vampire-witch hybrid children, Benjamin's past activities, and about The Book of Life. Matthew discovers a letter that implies that Benjamin may be in Central Europe.
After awhile, the twins are christened at the goddess' altar near Sept-Tours with Knights of Lazarus and others attending, and at the nearby church. Baldwin shows up at the church and Matthew tries to coerce him into agreeing to the establishment of Matthew's scion. Marcus tells everyone there that Matthew's blood rage is under control and that the Knights of Lazarus will support the existence of the scion. Diana tells Baldwin she will magically spellbind any vampires in Matthew's scion who act on their blood rage. Benjamin's stillborn daughter's fetus is discovered to have been brought to the church, with a threatening note.
Matthew tells Diana he wants to grow old with Diana. Diana gives him a holiday gift of some silver hairs among the black. Although Matthew is the head of the Bishop-Clairmont family, he says that Diana is its heart, and the heart is more important. Ysabeau gives ponies to the twins for the winter holiday, and her horse Rakasa to Diana. Jack shows his gift: an emblem design to represent the new scion. Matthew leaves to find Benjamin, and Diana goes to Oxford to find The Book of Life and insert the missing pages. They know someone of Gerbert's or Benjamin's is watching them.
Diana speaks with Matthew by phone when he is near Germany. She reminds him to be careful, especially because the goddess warned her that she would have to give up something if she wants to possess Ashmole 782. He tells her to remember that only love makes us truly immortal.
Diana and those with her try various unsuccessful methods to locate Ashmole 782 in the Bodleian Library, but she does not use Corra for this because she is afraid of what might happen. When she goes outside for some air, Gallowglass appears and tells her that Benjamin has Matthew. She realizes that Matthew is essential to her, and that to save him she will have to give up her fear of her own power. She goes back inside the library and lets Corra help find the missing Ashmole 782, which is hiding in plain sight in the library's book holding cage. Corra is freed from being Diana's familiar, although her power stays with Diana. Diana puts the missing pages back into the book, seeing that the book contains vast knowledge, including that the Bright Born are vampire-witch hybrids, which is what the twins Philip and Rebecca are. Then, all of the contents of the book transfer into Diana's eyes and on her skin.
Baldwin sends Diana to Venice to represent the de Clermont family at the Congregation meeting, to seek its support as the family and the Knights of Lazarus go to rescue Matthew, and to stop Benjamin from continuing his centuries of raping and killing. Baldwin tells Diana that he knew Matthew was ready to lead his own family because he didn't succumb to blood rage in the church when Baldwin challenged him.
Diana brings The Book of Life and goes to the meeting in Venice. Diana realizes that Satu is a weaver. She meets Congregation members, daemons Osamu Watanabe and Tatiana Alkaev, witch Sidonie von Borcke, and a friendly witch, Janet Gowdie. Gerbert Cantal and Sidonie von Borcke want to prosecute the de Clermonts, and Domenico Michele doesn't want to accept that Diana is Philippe's blood-sworn daughter. Gerbert and Domenico want to destroy all the vampires with blood rage and their children. Diana opens The Book of Life for the Congregation members, who realize it is made from the bodies of creatures. They see that the text has transferred to Diana's skin and eyes. Diana explains that weavers were killed because other witches feared their power. Janet reveals that her ancestors include a witch-vampire hybrid, and a witch called Isobel Gowdie whose lover was the vampire Benjamin, also called Nickie-Ben by the witches in her home country of Scotland. Diana finds out that the Bright Born, such as Diana's children, may live much longer than a human life span, retaining their youthfulness until the end. Sidonie accuses Janet of sullying her family's reputation by admitting that it is mixed witch-vampire. Diana thinks that people like Sidonie use the covenant as an excuse for their fear and dislike of those who don't conform, but that by blending the different types of creatures their special abilities would be better retained over the generations. After the meeting, Janet shows Diana that she has a concentration camp prisoner number just like Philippe did. Philippe was captured when he was trying to liberate the camp, Philippe obtained her promise to assist Diana when she met her at some future time. At Janet's suggestion, Diana obtains Satu's vote for the de Clermont motion by threatening her with exposure as a weaver. Satu would be at risk from Benjamin as well as the Congregation, unless the covenant is revoked. Satu is not sorry for having tortured Diana in the past and threatens Diana's children. Diana spellbinds Satu so she can no longer perform magic. The de Clermont motion wins the next day.
Diana joins Baldwin and the others in Chelm at the buildings where Benjamin has imprisoned Matthew. Under Fernando's leadership, the Knights of Lazarus successfully kill Benjamin's vampire children who are outside the buildings, enabling Diana and Janet to discreetly remove Knox' magical protections from the perimeter of Benjamin's stronghold. Diana sees Matthew in agony in a number of rooms, but they are only Knox' magical illusions. Finally, Diana uses magic to blow off all the doors and runs into Knox. Knox reveals that he killed her parents, that he stole Emily Mather's thoughts and stopped her heart, that he wishes that he had magically opened up Diana to find her secrets, and that he believes Benjamin will force her to bear Benjamin's children so that stronger witch-vampire hybrids will be created. He thinks witches will rule over the other warmbloods and the vampires. Diana uses her weaver's magic to enable the spirits of dead weavers from the Book of Life to destroy Knox and to avenge her parents and Emily.
Diana finds a beaten and broken Matthew with Benjamin holding a spike through Matthew's carotid - if Benjamin lets up on the pressure of the spike, Matthew will quickly bleed out - he has very little blood left. Baldwin and Ysabeau arrive in the room, Benjamin tries to enrage them and turn them against Matthew by disclosing that although he (Benjamin) was the one who tortured Philippe, Matthew was the one who actually killed him (at Philippes' request - out of mercy). Diana uses the tenth knot in a spell to shoot the goddess' arrow and kill Benjamin. Diana uses magic to bind the spike in place to protect Matthew from bleeding out once the spike is no longer being held in place by Benjamin. Matthew whispers that he couldn't die without saying goodbye as he promised. Love and time would be needed to heal Matthew, as well as Ysabeau's blood. Afterwards, as Matthew slowly recovers at home from the severe damage caused by Benjamin, holding the twins and being close to Diana help heal him body and soul. It is difficult for Diana to see Matthew struggle, and she feels anger, fear and frustration. Eventually, Matthew asks Hamish to bring some books, they play chess, and they talk with each other. Diana reads to Matthew, family members visit with them, and Matthew continues to slowly improve. After Sarah expresses concern over Diana, Baldwin arrives and orders Diana to take better care of herself while taking care of Matthew and the twins. He also orders her to answer his email messages. After he leaves, she opens her laptop, sees there are messages, closes it and returns to Matthew and the twins.
One night, Diana wakes to Matthew's touch. His damaged hands are working again. He strokes her and sees words from The Book of Life on her skin. He says that he sees her, even when she hides from the rest of the world. "I hear you, even when you're silent," a pure definition of love.
Baldwin and Matthew tell Diana she must go to Venice to meet with the members of the Congregation and seek an end to the covenant, with the argument that it was established due to Medievalists' fear of an imbalance of power among the types of creatures if more powerful, mixed bloodlines were allowed to exist. Instead, inbreeding has led to a lessening of the witches' power and fertility, the Vampires' ability to create new vampires, and the Demons stability. To make this argument, the existence and persecution of blood rage vampires would have to be discussed with the Congregation. Diana would argue that upbringing and self-control would help with the symptoms of blood rage. The entire family (and several other supporters) work to gather documentation from the time when the covenant was created to support Diana's argument to dissolve the covenant.
Miriam Shephard and Chris Roberts bring lab evidence to Diana and Matthew that having some daemon DNA is part of what enables witches to become weavers and blood rage vampires to conceive children with weavers. The conclusion is that the creatures are not a completely separate species, thus the covenant isn't relevant. Creatures are just humans with a difference. Diana also discovers that Gerbert had been feeding information about the de Clermont family to Benjamin for centuries. Ysabeau's spying while in Gerbert's house enables her to coerce his cooperation in the Congregation's vote to abolish the covenant, especially since Gerbert had been consorting with daemons and even illegally turned one into a vampire.
Overturning the covenant was the goddess' justice for the creatures who had been persecuted. After the meeting, Diana reports to her family that the covenant has been repealed. Baldwin appoints Diana to continue as the de Clermont family member of the Congregation. Diana sees the ghost of Philippe, who appears whole and is smiling. He tells her he is proud she destroyed the covenant, and that Emily and Diana's parents know she loves them. Philippe mischievously says that he wants Diana to have more laughter, more dancing, and more of his grandchildren. He returns the goddess' arrow to Diana - telling her that the goddess wants Diana to continue her work seeing that justice is done, taking over the task that had been Philippe's while he lived. Diana goes to Matthew and they dance together. Diana realizes that she will not have to bear this burden alone as long as she has Matthew.
Diana goes back to the library, realizing that The Book of Life in her body includes elements of witch, daemon and vampire. She can use her abilities for justice rather than pursuing vengeance or power. Matthew is researching with Chris Roberts, Miriam and Marcus in Chris' lab, preparing to reveal someday the genetic basis of creatures as part of human evolution. Matthew and Diana see a picture of Sarah and Agatha happy together on holiday, now more than a year after Emily's death. They discuss the birthday party coming up to celebrate the date of Matthew's rebirth as a vampire. They see Jack's new painting of them, Diana realizing that a willingness to change is the secret of survival, and that the combination of their opposite characteristics makes them both stronger. Diana and Matthew were the tenth knot, unbreakable, without beginning or end.