On the train back to Oxford after visiting the Guild, Lilian resolves to stop thinking about the mystery and become “settled Lilian. Calm Lilian” (109). In Oxford, she seeks out Harry and they go to dinner. She tells him about having been attacked in London and about Caxton’s plan for her to inherit the bookbinding business. On the walk home, they kiss and Harry explains that he wants to court her properly. He will speak to her father about advancing their relationship and exploring the possibility of marriage.

Lilian goes into the bookshop and enters the office, where she finds the man in the bowler hat (who attacked her in London). He demands to know where the books are; he holds a knife.

The man threatens Lilian, demanding the books. He references her father’s debts, making clear he knows their situation. Lilian retrieves the two Bell books (A Song for a Knave and He Sings His Devotion). Because she has previously removed the handwritten pages, those are not included. She gives the man the two books, but he presses the knife under her chin, demanding the other. She insists she has none. He warns he will return and leaves. Shaken, Lilian locks up and resolves to seek Charlie’s help in tracking and obtaining another Bell book because she knows the man will come back seeking it.

Lilian rises early, leaves Caxton a note claiming she cannot work because she is ill and goes to Harry’s house. She gives him a poetry book with the letters hidden inside it and tells him to keep it safe. She travels to London and approaches Grieves’s shop, where she meets Charlie and begs him to help her find out where the other Bell book went. Charlie agrees to search Grieves’s ledger and tells her to meet him in a few hours.

While she waits to reunite with Charlie and hear what he found, Lilian goes to the offices of a London newspaper that has been active since the 1850s (the era described in the letters). She persuades a young secretary named Evelyn to give her access to the archives. Based on information from the letters, Lilian identifies a time frame for the regatta referenced in Isabel’s letter (where Isabel and William hoped to run into each other). She is surprised to see that the society pages from that week have been deliberately cut out. Several other weeks form later in 1851 and 1852 have also been removed.

Lilian tells Evelyn about the missing pages, and Evelyn offers to investigate. Lilian leaves Evelyn her contact information and asks to be informed if Evelyn finds any record of a man named William Heathfield.

Charlie and Lilian meet at a café. She tells him about the missing pages in the newspaper archive and her theory that someone is trying to wipe all traces of William Heathfield from history. Charlie tells Lilian he looked at Grieves’s hidden ledger: the third Bell book was sent to a man named Mohan Chand. Lilian knows that Chand is a London bookbinder and recalls meeting his wife on the train right after she acquired the first Bell book.

Charlie and Lilian go to Chand’s shop. She claims to be looking for an Abel Bell book because her dying father is a fan. Chand mentions that his wife also loves novels by Bell and that she is currently away travelling. He shows Charlie and Lilian a copy of a Bell novel titled Orpheus in the Tower; Lilian discreetly looks at it and confirms that it has the same pattern of pinprick symbols as the other two (and is thus part of the set of six novels). However, Chand refuses to sell, explaining that his wife collects Bell’s work and has not yet seen this volume. While Charlie distracts Chand, Lilian impulsively steals the book. Chand realizes the book is gone but Lilian is already running away.

Charlie catches up to Lilian and comforts her. Lilian is touched by his efforts but conflicted about her feelings for both Charlie and Harry. Although Charlie invites her back to his rooms, she hurries away.

While awaiting a train back to Oxford, Lilian examines the book. She confirms (based on the pinprick code) that it is the fifth book in the set (Knave being first, Devotion third). Hidden inside the binding, she finds more handwritten pages, also numbered and initialed. She begins reading them.

The handwritten pages continue Isabel’s story. After their initial chance meeting, she and William fell in love. They regularly met in secret (aided by Daisy, Isabel’s maid) and exchanged letters; William also sent her copies of novels by Abel Bell (his favorite author). Isabel’s father planned for her to marry a cruel and wealthy man named Lord Beauchamp, and she played along with the engagement while secretly planning to run away with William. To fund their elopement, Isabel had Daisy sell her valuable jewels.

Eventually, Daisy is caught selling the jewels and reveals the secret relationship. Isabel’s father and her uncle, Silas confront her; they have abducted and severely beaten William. They threaten to kill him if she ever sees or writes to him again. Fearing for his life, Isabel agrees to marry Beauchamp and never see William again. Afterwards, Isabel’s father tells her that he has disinherited her; his wealth and property will not pass to her, but to his future grandsons.

After the confrontation, Isabel finds out that she is pregnant with Willam’s child. Her father is furious but keeps the secret because he wants to ensure that she still marries Beauchamp. Isabel writes to William, telling him about the pregnancy. Despite the efforts at secrecy, Beauchamp hears rumors about Isabel’s chastity and demands to have his own physician examine her. Her father is desperate to avoid her pregnancy being detected and makes a sinister comment: “if you were no longer carrying that bastard, then all my problems would be solved” (152). The letter breaks off.

Lilian makes her way back to Oxford, fascinated by the additional clues that might make it possible to identify the author of the letters. At home, she interrupts a meeting between her father and a man who is interested in buying the shop. Lilian is horrified that her father is thinking of selling the shop, but he laments that there is no other way. The debts are very high. Lilian resolves to bargain with the bowler-hatted man when he comes back to claim the next book.

Lilian confesses to Caxton that her father is dying and burdened by debt. Caxton reveals that Lilian’s father accrued debt during a period of deep grief and heavy drinking after her mother’s death. A knock on the door prompts Lilian to look outside and she sees the bowler-hatted man. She goes out to speak to him and tells him that he can have the remaining Bell books in the set in exchange for 4000 pounds—half upfront, half on completion. This money would be enough to settle her father’s debts and stabilize the finances of the shop. He agrees to consult his employer.

Several uneventful days pass. Harry tells Lilian he has spoken to her father and taken a new job as a typesetter at the university press, training to be a printer. He proposes marriage. Lilian is hesitant and fearful that being with her will endanger Harry. She tells him that when “this business with the books” (166) is over, she will reveal everything and he can decide then if he still wants to marry her.

Walking to Lilian’s home, they find the bookshop door broken open and the shop ransacked. Her father is unconscious but alive. A note addressed to Lilian reads that her offer is declined. Police soon arrive and her father is taken to hospital. Harry comforts Lilian, who is overwhelmed with fear and hatred, blaming herself for her father’s injuries.