The novel begins a year before the main storyline, when Hugo traces the letters “SOS” in the sand of the Five O’Clock Beach. He contemplates how long he has remained on Clock Island with his old friend, Jack Masterson, and how he should leave it behind, though he doesn’t know where he’d go. He feels conflicted because leaving would mean abandoning Jack. For years, Jack has shown a complete apathy toward the world, drinks too much, and is generally depressed. That night, however, the light in his writing factory turns on for the first time in six years, meaning that Jack is finally writing again.

The narrative changes to an excerpt from Jack Masterson’s first book, The House on Clock Island. In the excerpt, a girl named Astrid wakes up because her room is flooded with light from a lighthouse. Knowing what that light means, she wakes her younger brother and tells him that the Mastermind has returned to Clock Island.

A year after Jack began to write again, Lucy Hart is clearing up the mess made by the children she oversees in Ms. Theresa’s classroom. Christopher, a student, comes to find her and helps clean the classroom.