A. D. Bell’s The Bookbinder’s Secret is a dual-timeline historical mystery set in England in 1901. The novel follows Lilian Delaney, an apprentice bookbinder whose curiosity about a damaged book pulls her into a 50-year-old scandal involving forced marriage, a hidden child, and a contested inheritance. Across both timelines, Bell develops themes such as The Cost of Obsession, Women Confined by Gendered Exploitation, and Truth-Seeking Through Attention to Detail. Published by St. Martin’s Press in the United States in 2026 (originally by HQ in the UK in 2025), The Bookbinder’s Secret is Bell’s first novel.

Content Warning: The source material and this guide feature depictions of graphic violence, illness and death, physical abuse, emotional abuse, sexual content, pregnancy loss and termination, and substance use.

Plot Summary

In October 1901, 25-year-old Lilian Delaney lives in Oxford, England, and works as an apprentice for bookbinder John Caxton. Lilian lives with her widowed father, who runs a struggling bookshop. Lilian travels to the home of Dr. Ashburn, who has commissioned her to rebind a book. As she leaves, Ashburn gives her a fire-damaged book titled A Song for a Knave by Abel Bell. Ashburn explains the book was sent to him from a London bookseller named Grieves, but he does not want it.

On the train home, a woman named Mrs. Chand strikes up a conversation with Lilian after noticing the damaged book. Mrs. Chand is married to a bookbinder named Mohan Chand and her comment about her husband hiding his mark beneath the back endpaper prompts Lilian to later take a closer look at A Song for a Knave. Lilian finds a scrap of paper with the sentence “I wish you hadn’t killed him” in a woman’s handwriting, as well as a fragmentary letter. She also finds a binder’s mark, the initials FFG, and tiny pinpricks arranged like dots on a playing card.

Lilian travels to London to meet Grieves, who is defensive but admits to having sold one other book by Bell. As Lilian leaves his shop, a sinister man in a bowler hat attacks her, briefly taking possession of the book before Charlie (a young man who works in Grieves’s shop) recovers it. Charlie later gives Lilian additional information: Grieves was commissioned by an unknown client to acquire a set of six books written by Bell. Grieves acquired three but then refused to collect any more. Grieves sold one book, sent another to Ashburn (this is the one Lilian has), and the third is still in the shop, soon to be sent away. Charlie offers to get it for her, and days later, Lilian returns to London where Charlie gives her He Sings His Devotion (another novel by Bell, bound in the same way).

Lilian finds handwritten letters hidden inside, recounting events from 1851. The writer is a beautiful and aristocratic young woman, whose father wants her to make a profitable marriage. The letter describes a chance meeting with a man named William Heathfield, hinting that the two fell in love and their lives became intertwined. Lilian can deduce that these pages are part of a larger document; clues and coded markings on both the Bell books suggest that they are books 1 and 3 from a six-book set. Events escalate when the bowler-hatted man breaks into Lilian’s home in Oxford, threatens her, and leaves with the two Bell books (Lilian retains the handwritten letters, which she has hidden separately). The man tells her he will return and Lilian becomes desperate to obtain another Bell book to pacify him with.

She returns to London, where Charlie confirms that Grieves sold the third Bell book to the bookbinder Mohan Chand. Chand refuses to sell the novel (Orpheus in the Tower) but Lilian steals it. The coded markings reveal that this is Book 5 from the set; the handwritten pages hidden inside describe how Isabel pursues a secret relationship with William despite being engaged to a wealthy lord named Beauchamp. After her father uncovers the relationship and threatens to kill William, Isabel breaks it off. Her father disinherits her, changing his will so that her future son (his grandson) will inherit. Isabel discovers that she is pregnant with William’s child.

Hoping to alleviate her father’s financial problems, Lilian negotiates with the bowler hatted man, offering to get the remaining books from the set in exchange for money. Days later, she finds the shop ransacked and her father unconscious: He suffered a heart attack when the shop was broken into. A note at the scene reveals that Lilian has only two weeks to produce the remaining books. Lilian travels to Manchester to meet the publishers listed on the books, who direct her to a collector named Ambrose Fane. Fane confirms that he has another Bell book from the set: Love’s Last Aria (the fourth in the set). Lilian steals the handwritten papers from inside, leaving the book in Fane’s library.

This next set of pages provides context for the events between William and Isabel’s first meeting and the confrontation with her father months later. They fell in love, eloped, and were secretly married: Any of their children would be legitimate and thus able to inherit. The man with the bowler hat returns to Lilian’s home, where he assaults her, steals the only Bell book she has in her possession (Orpheus) and forces her to reveal that Ambrose Fane possesses one of the books from the set. Days later, Fane finds Lilian in Oxford and reports that Devlin (the bowler hatted man) paid him for the Aria; Devlin and whoever he is working for now possess four out of the six books.

Fane gives Lilian a lead on the next book: someone named Fahig Peal bought a Bell book for an unusually high price at auction years ago. With a begrudging clue from Grieves, Lilian deduces that Fahig Peal is a code name for Abel Bell. She reaches out to Bell via his publisher (Montague), pleading to meet him. Meanwhile, Lilian’s father dies due to injuries he sustained during the break in. Devlin steals the handwritten documents which she has been hiding in her home, revealing that her adversary knows about the secrets hidden within the Bell books and is interested in those, not the books themselves.

After her father’s funeral, she travels to Manchester, where she is finally directed to Bell’s home and meets two women: 74-year-old Deidre, who began writing as Abel Bell at 18, and her granddaughter Agnes, who continues the books. They give her the sixth volume, When Love Lies Unsung, and provide her with information about the Chatton family. Isabel was the daughter of Malcolm Chatton and niece to Silas Chatton; Silas has a daughter, Julia Chatton, who is alive and actively trying to acquire the six books in the set. The new pages describe Isabel giving birth to a son, Isaac William, in May 1852; the baby was delivered by a physician named Dr. Ashburn (the father of the man who gave Lilian the first Bell book). After Malcolm ordered Dr. Ashburn to kill the baby, the doctor hid the infant with his own family to protect it.

After giving birth, Isabel carefully documented a testimony of her experiences, had the document notarized, and then concealed it along with the marriage and birth certificates establishing her son’s legitimacy. Meanwhile, Silas became volatile and dangerous after the death of his son; months earlier, when Isabel was still pregnant, her father and uncle conspired for her to marry her cousin, Julian (Silas’s son). William found out about the engagement and killed Julian in a secret duel. Although there is no proof, Silas is obsessed with finding William and getting revenge. Silas kills Malcolm, leaving Isabel more terrified than ever.

After learning about the Ashburn family’s connection to the Chattons, Lilian goes back to see the younger Dr. Ashburn. He shows her his father’s journals, which corroborate Isabel’s story and provide new information. After Isabel’s testimony was complete and concealed, the elder Dr. Ashburn found William Heathfield beaten to death by Silas’s men. He told Isabel about what had happened and kept the baby to raise in safety. Isaac is now a doctor who lives in America. The younger Dr. Ashburn doesn’t know what happened to Isabel. At her urging, his father did try to find the six books, but he could only ever locate one. Ashburn shows Lilian The Lyre’s Broken String, the second book in the set. Inside, Lilian finds the final pages of Isabel’s testimony along with Isaac’s birth certificate and Isabel’s marriage certificate.

Ashburn then reveals that Julia Chatton married a bookbinder named Mohan Chand. Lilian realizes that Julia is Devlin’s employer, and the antagonist who has been trying to obtain the documents hidden within the Bell books. Lilian writes to Julia, challenging her to settle the conflict once and for all. They meet and Julia reveals that her own son stands to inherit the Chatton fortune, so long as Isabel’s documentation about Isaac’s claim never surfaces. The two women fight; Julia burns the confession pages in the fireplace, but a spark catches and fire spreads. Lilian attempts to help Julia but flees to save herself. She later learns that the house burned down and Julia died. With the six books in the set assembled, Lilian solves a puzzle that Isabel referenced in her testimony: an acrostic spelling out ATHLOW GRANGE.

Lilian travels to Athlow Grange, an isolated country estate, where Isabel Chatton has been living for more than 50 years. She tells Isabel about her son and affirms that solving the mystery has changed her life. Lilian then returns to Oxford; Caxton has cleared the debts on her father’s business and offers her a partnership in a combined bindery and bookshop business. While solving the mystery, Lilian has also gradually been reconciling and building a new relationship with her childhood sweetheart, Harry. Harry has helped her loyally, and at the end of the novel, they decide to begin a life together. In the final scene, when Lilian has given up on solving mysteries, Harry presents her with a mysterious book he has recently found.