Twelve and a half years before the start of the novel, Jameson and Grayson Hawthorne, seven and eight years old, conspire to set the clocks forward at Hawthorne House to get around their grandfather’s rule: “On Christmas morning, you may not step foot outside your rooms before the clock strikes seven” (1). They meet their oldest brother, Nash, and their youngest brother, Xander, in the Great Room to find that all the Christmas decorations and presents are missing. A single ornament cues the brothers to look for clues on the six other lavish Christmas trees in the house. The clues lead the brothers outside to a far corner of the estate where their grandfather presents them with a multistory tree house.

In the present day, Grayson Hawthorne practices knife fighting at Hawthorne House while Xander Hawthorne chides him, “I just think you could do with a little more balance in your life [...] An actual hobby? Down time?” (8). Grayson and Xander receive a text message from Nash that reads “Nine-one-one” (9).

Jameson Hawthorne and Avery Grambs are visiting Iguazu Falls when Jameson receives the 911 text from Nash. Each Hawthorne brother may use a 911 call once a year: “The code didn’t mean emergency so much as I want you all here, but if one brother texted, the others came, no questions asked” (11).