It's Doomsday (the beginning of school) minus four, and twins Hunter and Zack have just remembered they're supposed to read and report on three books that have changed their lives. Then they learn from a classmate that their younger brother, Steadman, may be the target of a kidnapper. Although their source is annoyingly vague, the boys take her seriously. They construct a tree-house lookout and search for clues, noting suspicious strangers in an abandoned house, the neighborhood bully poking at something hairy in the pond, and a mysterious letter intended for their mother (who is in the hospital giving birth to sibling number seven). This sequel to Hunter Moran Saves the Universe (2012) combines mystery and farce in a wild-goose-chase romp that includes late-night rendezvous in Werewolf Woods, tumbles from classroom windows, and skateboard rides down Suicide Hill. The characters are reminiscent of Hilary McKay's Cassons, and readers will appreciate Giff's gentle message that even exasperating relatives (including Fred, the family's untrained pooch, who is kidnapped) are worth defending.