With a POP! and a puff of smoke, the Willows' lawn mower calls it quits. A new mower will cost their parents a lot of money, money Derek had hoped to borrow for a train ticket to visit a friend. Luckily Derek and his brother and sisters find a rusty push mower tucked away in the shed. It doesn't look like much, but it turns out that it's been soaking up magic for years. And it's hungry for grass!

Can Derek earn his ticket? Maybe . . . if he, Abner, Tate, and Celia can keep the magic mower under control!

Lynne Jonell follows up her Junior Library Guild selection, Hamster Magic, with a second story of the Willow family's rowdy run-ins with mixed-up magic.