TALES OF A FIFTH-GRADE KNIGHT

Heroic deeds await Isaac after his little sister runs into the school basement and is captured by elves.

Even though their school is a spooky old castle transplanted stone by stone from Germany, Isaac and his two friends, Max and Emma, little suspect that an entire magical kingdom lies beneath—a kingdom run by elves, policed by oversized rats in uniform, and populated by captives who start out human but undergo transformative “weirding.” These revelations await Isaac and sidekicks as they nerve themselves to trail his bossy younger sib, Lily, through a shadowy storeroom and into a tunnel, across a wide lake, and into a city lit by half-human fireflies, where they are cast together into a dungeon. Can they escape before they themselves start changing? Gibson pits his doughty rescuers against such adversaries as an elven monarch who emits truly kingly belches and a once-human jailer with a self-picking nose. Tests of mettle range from a riddle contest to a face-off with the menacing head rat Shelfliver, and a helter-skelter chase finally leads rescuers and rescued back to the aboveground. Plainly, though, there is further rescuing to be done.

A fizzy mix of low humor and brisk action, with promise of more of both to come.