The Dark Flight Down
 Five days after New Year's Eve and Valerian's death, Boy and Willow have been separated by Kepler, who needs Boy further, and is determined not to let Willow get in his way. The two set off for the funeral of Korp, the director of Valerian's old theatre. To Kepler's chagrin, Willow is also there, having snuck out from the previous job that Kepler got for her at a local orphanage. The theatre violinist, Georg, insists on dragging Boy and Kepler off to a local tavern. Willow follows, and, despite Kepler's attempts to leave, he is dragged into a game of Snapdragon, which he finds he is not very good at. Meanwhile, Boy and Willow, finally reunited, discuss the possibility of abandoning Kepler and eloping together. Discovering Kepler is unconscious after drinking too much absinthe, Boy decides to return him home, and is offered help by Wilfred, the strongman. Before leaving, Boy and Willow make plans to meet at the St. Valentine's fountain, and share their first kiss. The next day, Boy seeks out the mysterious Book that Valerian had sought, and Kepler had taken, in the hope he will find out whether or not Valerian really was his father, and what is real name is. However, a hungover Kepler arrives and orders Boy to return to Valerian's house to collect the Camera, which Valerian had spent money having built in order to determine when Fate was coming. At the house, Boy finds the Camera, but before he can retrieve it, he is apprehended by some members of the City Watch, who suspect him of looting. Boy is dragged off to the Palace, where the ancient Emperor Frederick lives. At the St. Valentine Fountain, Willow grows angry at Boy's no-show, and storms off to Kepler's to confront him. There, she discovers that Boy has not returned, and they set off to look for him at the Yellow House. Upon arrival, they find signs of a struggle, and find the Camera, which Kepler had sent Boy to find. Knowing where Boy is, Kepler insists on rescuing Boy alone. Willow, however, heads to the Palace and tries to find a way in. Unable to, she runs into Kepler, who decides to help. At the Imperial Palace Court, Boy is presented to the Emperor Frederick by his shaven-headed servant, Maxim. Frederick, an elderly and hypochondriac who is obsessed with his health, living an extravagant lifestyle and finding immortality, is uninterested in the findings and orders Boy be thrown into the river. Before the City Watchmen can do so, however, Maxim intervenes and instead has Boy dragged down to the castle dungeon. Boy soon picks the lock of his cell and tries to get out, but is unable to. In his wait, he is troubled by dreams of a dark flight of stairs, leading to where he believes the Phantom, a savage murdering creature from the previous book, is kept. Eventually, a blinded jailer brings him some food, and is carrying a second one for another prisoner, whom Boy is unable to see. Maxim questions Boy about the Book, believing Valerian had it. When Boy is unable to answer, Maxim grows frustrated and leaves. It emerges that Maxim is seeking the Book because Frederick, determined not to die, as he has no heir to the throne, and is the last in line for his family, is attempting to find a way to become immortal, and is relying on astrologers, alchemists and necromancers to help him, and if a person does not impress him, he has them killed. Maxim hopes that the Book will provide the answer. Boy further investigates the dungeon and, further away from his cell, he meets an elderly man, who lives in a guilded, well-furnished cell within the dungeon. The man, whose memory has left him, introduces himself as Bedrich, and reveals that he is Frederick's former doctor. He is now meant to take care of the Phantom, which resides within the Palace. The next time a meal is brought, Bedrich is brought with it. He is told he may be released. Sensing an opportunity to get help, he asks Bedrich to send a message to Willow, telling her to steal the Book (from Kepler, though this is not verbally mentioned) and return. Bedrich starts to tell Boy that he knows about this "Book," and upstairs, Frederick questions Maxim about Boy. Having forgotten he had ordered Boy's death, he demands that Boy be cleaned up and brought to him. Back downstairs, Bedrich reveals that the Book is not only full of knowledge, but also very dangerous. It was brought to Frederick by the Beebe family (the grave of Gad Beebe having been the one Boy and Valerian had attempted to retrieve in the previous book). Before he can go on, two guard arrive and take boy away, leaving Bedrich in the cell, and it is revealed that their interaction was actually being spied on. Boy is taken to some luxurious quarters, where he is given a bath, some food and clothing and a bed by another blinded servant. The next morning, he is interrogated again by Maxim, who seems to know exactly what has been said, and about Willow. Boy realises he was spying on the meeting, and feels awful at having betrayed Willow's name. He is taken down to the Court, where Frederick is holding a meeting of applicants for a Royal Position. Boy immediately impresses Frederick when he exposes a secret that an alchemist is using to try to prove his alchemy, leading to the man's death. The next demonstrators turn out to be Kepler and Willow, who introduce themselves as Arbronsius and Mina. They show Frederick the apparatus that Boy had been sent to collect. The demonstration of the trick is enough to win them Frederick's favour, and he appoints them to Royal positions. That night, Boy manages to work out where Willow and Kepler are staying, and, after escaping from his room, goes out to find Willow. As he is crossing the snowy courtyard, he runs right into The Phantom, which is even scarier than he had expected. The next day, Maxim storms into his room, angry, because Willow was not at the orphanage. He eventually explains to Boy that he hopes the Book will provide the answer to immortality. Boy scoffs at this idea, mentioning that "How's he going to know any different unless he dies." Maxim has an idea, and drags Boy down to the Court. There, Boy manages to talk to Willow and Kepler. Maxim lies to Frederick and says that he does have the Book, and Frederick decides he does not wish to see it, as it might evoke bad memories, and believes Maxim. Boy arranges to meet with Willow that midnight. That night, as Maxim is planning his next move, Boy meets up with Willow in the throne room. Boy discovers that Kepler was indeed lying about Valerian being his father, as the mention of the woman Valerian had loved, Helene, was enough to persuade Valerian that Boy was his son. He discovers that Kepler has the book with him, and refuses to leave until he reads it. The two make a plan to try to retrieve the book before Frederick becomes immortal, and share a brief kiss before departing. The next day, Maxim calls a meeting of the Court, planning to use Frederick's immortality to advance his own power. To his dismay, Boy, whom the Emperor has drawn a favourable eye towards, is made to attend. Maxim goes through an elaborate ceremony, and gets the Emperor to drink a potion behind some screens. Frederick falls asleep for a few minutes, before waking, believing himself to be immortal. Boy realises, however, that it is a trick. Before the guards can kill the astrologers, Boy immediately steps forward and shouts that it is a trick, mentioning the very fact that Frederick cannot conclusively prove he is immortal unless he dies, as he himself had said. Frederick chooses to listen to Boy and demands the Book. Trapped, Maxim confesses that he was lying and, after many years of being pushed around, finally explodes at the Emperor, who orders that he be killed. Before the guards can get him, Maxim escapes through a secret door, and Frederick orders the guards to search for him. Boy and Willow take advantage of the confusion to try to flee from Kepler. Willow escapes, but Boy is caught by Kepler. At that moment, Maxim returns - with The Phantom on a chain. He reveals that Frederick does have a son - that fifteen years before, one of Maxim's consorts, Sophia Beebe, fell into a relationship with the Emperor. The son that she produced was, in fact, The Phantom, who is, technically his heir. Frederick orders his guards on Maxim, but the Phantom escapes, as does Boy. Boy escapes to Willow's quarters, where he finds her reading the Book. Boy demands to know what she has read, so he can finally know his name and his history. Willow, however, begs him not to read it, saying that it is not in his interests to, but he insists on knowing. Before doing so, Willow finally tells Boy that she loves him. She then informs Boy that his father is none other than the Emperor Frederick. She reveals that Sophia Beebe, The Phantom's mother, had given birth to two sons - Boy was the second one, while the Phantom is, in fact, his disfigured brother. When Frederick had locked away the disfigured one, Sophia had fled with Boy, her healthy child, faking his death. In response, Frederick stripped the Beebes of their favour and titles, all the while searching for Sophia. After proclaiming that he loves Willow back, Boy confesses that he does not care about his finding. Willow reveals that Kepler knows his secret, and Boy realises that Kepler had wanted Boy to curry favour from the Emperor by revealing his healthy son, and heir to the throne. Boy does not want to be heir, however. At that moment, The Phantom arrives at the balcony, but does not attack them. Instead, it approaches Boy, and the two share some brotherly affection. Suddenly, Kepler arrives and attacks The Phantom. The two fight, and fall over the balcony to their deaths. With both The Phantom and Kepler dead, Boy and Willow prepare to leave. Boy, however, throws the book into a fire. It is eventually ablaze, and burns, taking its evil and magic with it. The two leave the Palace, by jumping off the Palace walls. They spend the night at Kepler's. The next morning, Boy and Willow take the now-deceased Kepler's money, clothing, blankets and valuables. They plan to leave the City and, as two young lovers, set up their own future. Before leaving, though, Willow makes one final revelation - that "Boy" was, in fact, Boy's real name, as it was what Sophia had actually called him while the two were on the run. In a final scene, the Emperor Frederick, now suffering completely from dementia, calls for Maxim, whom he has had locked in the very cell that he imprisoned the Phantom in.