Xander Hawthorne spends a week studying the brief letter Tobias Hawthorne left him. The visible message, addressed to Alexander, says only, "Well done," which frustrates Xander because Tobias had promised that once the family game ended, Xander's own game would begin.

Xander reflects that he helped his brothers and Avery reach the end of Tobias's final challenge, but unlike his brothers, he has rarely had the chance to compete and win. When Avery opened the final box and Xander opened his envelope, he expected a riddle, puzzle, or clue, but the letter seemed disappointingly empty.

Unwilling to give up, Xander brings Rebecca and Thea as witnesses while he tests one last theory. After trying heat, ultraviolet light, and other methods for revealing hidden writing, he explains that one kind of invisible ink reveals itself in water but destroys the message afterward.

Xander submerges the letter despite fearing that he may be ruining his only chance. Hidden writing appears around Tobias Hawthorne's signature: the Roman numeral II on one side and the word "Find" on the other.

The revealed message gives Xander his true challenge: find Tobias Hawthorne II. The epilogue transforms Xander's disappointment into a new mystery, implying that Tobias's final game is not over and pointing directly toward the supposedly lost or hidden Toby.