Boo has survived the winter, loving his new home, fond of both the old cat, Lacy, and the old man and woman that care for him. Quite playful and very protective of old Lacy. When a fat rat moves in on Lacy's feed dish, Boo sets about to get rid of him. The problem is finding where he goes when he drops down the pipe hole under the kitchen sink. It takes quite some time to find the rat hideout. Boo has declared war on Fat Rat, made it his personal passion to get him gone, and they meet on several occasions before Boo finds the rat's home. And the fight is on. See what happens to Boo and Fat Rat! Suspence through the end any child should love.