In the ninth year of living with Mr. Webber, Cassie stops thinking of the future as distant and begins to feel time closing in. Watching Mr. Webber gradually weaken—longer naps, shakier legs, thinner frame—Cassie realizes these are his last seasons, and she hides her grief so she will not reveal anything he is not meant to know.

Cassie recalls trying and failing to warn her grandfather about his health, and she accepts that Mr. Webber’s decline cannot be altered. When Mr. Webber calmly tells Cassie that “the light is fading,” Cassie pushes back and distracts herself with pointless kitchen tasks, because she cannot bear the subject. Mr. Webber has become Cassie’s closest friend and her anchor, making the approaching loss feel unbearable.

During the summer of the year Mr. Webber will die—the same year Cassie’s other self will receive the Book of Doors—Cassie decides she must leave. In a quiet evening conversation with baroque music playing, Cassie tells Mr. Webber she needs to go, and Mr. Webber understands that Cassie’s past is about to become her present again. They speak about the Book of Doors, still a mystery in how Mr. Webber ever had it to give, and Mr. Webber warns Cassie not to waste her life hidden in her own mind.

Mr. Webber thanks Cassie for sharing the last ten years with him, calling them the best of his life, and promises he will still “look in” on her at Kellner Books, even if the other Cassie will not yet know the depth of their friendship. Cassie realizes that Mr. Webber’s repeated story about Rome was likely meant as a memory marker—something to prove Cassie’s identity when she first arrived in the past.

In early winter, Cassie leaves Mr. Webber’s apartment for the last time with money he has given her, a bag of clothes, and the phone she brought into the past, newly charged but kept off to avoid interfering with the other Cassie’s phone. After a final, lingering farewell—talking of books and Mr. Webber rereading The Count of Monte Cristo—Cassie walks away without looking back. She goes to Penn Station with a ticket south and a meeting in a few days, knowing she will soon return to New York to face what is coming.