When their home next to a brook is destroyed by beavers, a large family of golden mice is aided by Poppy the deer mouse and her grumpy porcupine friend, who in the process forges a relationship with the son he had abandoned.

Poppy, accompanied by her troublesome son Junior, his skunk friend, and Uncle Ereth the porcupine, responds to a summons to return to her ancestral home, Gray House, to save the mice there from destruction by a bulldozer.

While helping a young raccoon reunite with his mother, adventurous mouse Ragweed ends up in Dimwood Forest, where he meets and rescues a deer mouse named Poppy.