Tumtum and Nutmeg lead cozy and quiet lives, secretly looking after Arthur and Lucy, the disheveled human children of the cottage, never dreaming that so many exciting adventures will soon find them. But when evil Aunt Ivy, a squeamish schoolteacher named Miss Short, and pirating pond rats threaten the safety of those they hold dear, the courageous pair will stop at nothing to save the day.

In three thrilling tales of daring and wit, Tumtum and Nutmeg-along with veteran hero General Marchmouse, Ms. Tiptoe's bouncing ballerina army, and a team of caged gerbils--prove that small-size mice can have world-size hearts.