Cassie takes the Book of Doors to Mr. Webber’s building to look for answers, but the locked front door will not respond to the book. She realizes the book cannot make her pass through a locked door from the outside; it only works when she starts from an unlocked doorway.

To test this, Cassie uses an unlocked Citibank door as her starting point and successfully steps into Mr. Webber’s building hallway. After finding Mr. Webber’s apartment door locked, Cassie memorizes the door and repeats the trick, using the bank again to arrive inside the apartment. The book’s doorway illustration updates to match each new destination, confirming the magic is tracking the “last door” she’s connected to.

Inside, Cassie searches the tidy, book-filled apartment for anything like another magic notebook but finds only ordinary shelves and signs of a quiet life. In a smaller bedroom, she discovers clothes that seem to belong to a younger woman, raising questions about who else lived there. In Mr. Webber’s main bedroom and living space, Cassie finds nothing that explains why he chose her, leaving her frustrated and unsettled.

At Kellner Books, Cassie tries to learn more about Mr. Webber by questioning Dionne and Mrs. Kellner. Dionne remembers serving him but noticed nothing specific. Mrs. Kellner recalls Mr. Webber as a long-time, solitary customer and vaguely remembers him once leaving with a much younger woman, though she admits her memory may be mixing people up.

Later, Izzy arrives shaken after spending the day researching the “teleporty book” online and finding no trace of it anywhere, which makes her suspect information is being suppressed. Izzy urges Cassie to go to the police about Mr. Webber, but Cassie admits she entered his apartment using the book. As they walk, Cassie spots the same gaunt, dark-haired man from the Library Hotel terrace watching them; worried, Cassie uses the book to take Izzy back to Kellner Books, escaping his presence.