The Book of Doors

Cassie Andrews is closing up Kellner Books on a snowy night when longtime customer John Webber—gentle, talkative, and often rereading The Count of Monte Cristo—dies quietly at his usual table. Police and EMTs treat it as a natural death, but while cleaning Cassie finds a small leather journal left for her: the Book of Doors. Inside, a line reads, “Hold it in your hand, and any door is every door,” along with a personal message from Webber that soon vanishes from the page.

At home Cassie tells her roommate, Izzy Cattaneo, who dismisses the journal as nonsense until Cassie opens their apartment door and sees a rainy street in Venice—real air and raindrops crossing the threshold. They confirm the phenomenon, then begin experimenting: by visualizing a specific destination door while holding the book, Cassie can “set” any unlocked doorway to open elsewhere. A midnight spree across Manhattan proves the power is repeatable and even affects how a door must be opened. Izzy is exhilarated but alarmed by what the book could enable in the wrong hands.

Meanwhile Drummond Fox, a man marked by an old tragedy, is confronted in Washington Square Park by book-hunter Dr. Hugo Barbary. Drummond escapes using another special volume, the Book of Shadows, and later notices two women using a magic doorway at the Library Hotel—confirming the legendary Book of Doors has resurfaced. Elsewhere, Azaki, a book hunter with a bodyguard named Hjaelmer Lund, uses the Book of Illusion to conjure a cathedral in the Chilean desert and then heads for New York after being hired by Lottie Moore, a powerful broker known as the Bookseller, who is especially interested in Izzy.

Cassie tries to learn who Webber was by breaking into his apartment using the book’s rules (it cannot bypass a locked door directly, but she can enter via an unlocked “starting” door and target a remembered interior door). The apartment yields only unsettling hints, including clothes that suggest someone else lived there. Izzy’s online search turns up nothing about the book, and Cassie notices a gaunt man watching them. Soon, Drummond approaches Cassie and Izzy at Ben’s Deli and warns them that special books attract ruthless pursuit; he proves it by showing his own Book of Luck.

The warning becomes immediate when Barbary storms the deli, using the Book of Control to fling people through the air and trap everyone inside. Cassie escapes with Izzy and Drummond through a restroom door. In Lyon, Drummond explains the existence of special books and the secrecy around them, and he insists the safest option is to destroy Cassie’s Book of Doors. Cassie refuses. Back in New York, Drummond reveals the Book of Memories and forces it on Izzy, erasing her knowledge of recent events to protect her from hunters. Cassie is furious at the violation, but Drummond argues ignorance is the only shield that will hold.

Drummond then takes Cassie to his hidden Fox Library in the Scottish Highlands by traveling through a shadowlike in-between state created by the Book of Shadows. In a concealed vault he shows her seventeen special books and warns that people like Barbary—and worse—would weaponize them. He reveals the Book of Doors can also open into the past. Drummond discovers the library already contains an earlier, unreadable version of the Book of Doors acquired in 1918, implying a time-loop: Cassie’s readable copy is the same book at a later point in its own timeline.

Cassie tests time travel by going to 2012 in her hometown and meeting her grandfather, Joseph Andrews. She tries to warn him, but Joseph refuses to hear the future and instead urges her to choose happiness rather than hiding from life. While Cassie and Drummond are away, Izzy wakes with memory gaps and is questioned by “detectives” Azaki and Lund before Barbary invades her apartment, murders the detectives, and tortures Izzy with the Book of Pain to force her sealed memories back. Lund ultimately knocks Barbary out and flees with Izzy.

Cassie and Drummond return to Cassie’s ransacked apartment and find Barbary waiting. Barbary attacks, steals books, and uses his power to hurl Cassie through a doorway into the past, stranding her without the Book of Doors. Homeless and terrified, Cassie seeks out a younger John Webber. He doesn’t have the book yet, but after Cassie proves her story with private knowledge and her advanced phone, he shelters her. Days become months, then years: Cassie and Webber search for the Book of Doors, talk endlessly about books, and form an improvised family until Cassie accepts the only way home may be to wait for time to catch up.

When Webber finally sees Cassie’s younger self in Kellner Books, he fully believes Cassie, redoubles the search, and even chases a false lead from a collector named Morgenstern. Cassie pivots from searching to preparing: she secretly strikes a bargain with Lottie Moore in New Orleans. Lottie will protect Izzy and lend Cassie an heirloom, the Book of Safety, which makes its bearer impossible to injure—on the condition Cassie later surrenders the Book of Doors.

As the timeline loops back to the night Webber dies, Cassie watches her younger self receive the Book of Doors, then positions herself for Barbary’s ambush. Barbary captures Drummond and confiscates multiple books, including the Book of Doors, but Cassie—protected by the Book of Safety—fights back, steals Barbary’s gun, and helps Drummond reclaim the books. Refusing to kill Barbary, they open a door to 1970s New York and throw him through, trapping him in the past.

At the Bookseller’s secret auction of the Book of Pain in a decaying hotel, Barbary reappears aged and armed, murders guards, and unleashes stolen powers. Cassie and Drummond intervene, and a new horror arrives: a gray-mist woman wielding the Book of Light, who kills bidder Okoro and takes his Book of Matter. In the chaos, Izzy appears to be shot dead, Cassie flees into a voidlike “nowhere,” and months pass before she returns to the ruined ballroom and finds strange evidence—missing belongings and messages from Izzy’s phone.

On the Oregon coast, Cassie reunites with Izzy and Lund and learns the truth: Izzy survived because the Book of Illusion made her appear dead. Drummond also resurfaces, having shadowed them with the Book of Shadows. The group commits to a plan to kill the gray-mist woman, and Azaki is revealed to have faked his own death with illusion, later reclaiming his book.

They bait the woman with a staged auction, then secretly follow her through time in the shadows to learn she keeps stolen books in a basement safe. Cassie steals the cache via the Book of Doors and Azaki replaces the books with temporary illusions. In the final trap, the woman sees through the ruse, shoots Lund, and reveals the Book of Despair stitched into her skirt, crushing Cassie, Drummond, and Azaki with hopelessness. Only Izzy, protected by the Book of Safety, can act; she sets the Despair “skirt” on fire, breaking its hold. Cassie opens the Bookseller’s hidden mirror-door and Drummond uses his power to hurl the burning woman into the darkness beyond, ending her immediate threat.

Barbary’s fate ripples further back: in 2002, pain stripped from his mind becomes an intent-driven entity that possesses a tourist child named Rachel Belrose, setting the origin of the future gray-mist woman in motion. In the restored Fox Library, Drummond proposes a new mission: Cassie, Izzy, Azaki, and Lund will work with him to hunt and safeguard special books. The Fox Library’s earlier Book of Doors finally activates for Cassie, and she understands the loop must be completed—she must deliver it to John Webber so he can one day give it to her. Before returning to that duty, Cassie uses the Book of Joy to ease her grandfather’s final moments, transforming a defining trauma into peace, and then quietly ensures the Book of Doors reaches Webber at the destined time.