Referring to his late father's journal for advice on how to be the man of the house, young Isaiah taps the support and ideas of two school friends who help him navigate rules and manage without superpowers.

On an ordinary Monday, Rill Kruse left for third grade with a dad, but when she came home, he'd been stolen. By a river. One year and thirteen days later-on the first morning of summer vacation-Rill still insists he's trudging home. Her mom has become a practical woman. Her older brother, Eddy, now calls her baby and dork. Gus, second-in-command at Kruse Whitewater Adventures, Rill's family's rafting company, has gone from being her dad's "risk bro"...