Margaret's father died in a mysterious drowning accident when she was eight years old. Four years later, her mother still won't talk about it -- in fact, she doesn't talk about much of anything. But when Margaret's mother takes her and her little sister, Sophie, to a strange abandoned mansion and puts a FOR SALE BY OWNER sign in the front yard, Margaret is determined to solve the puzzle of her family, once and for all.

Armed with three strange clues -- a swimming medal, a key, and a handwritten comic book -- Margaret returns to the mansion alone. With the help of Boyd, the lonely, comic-book-obsessed boy next door, she discovers that truth can be stranger than fiction -- depending on who's telling the story.