Paddler cries for help from the pond because Rockmouth, the old pike, has bitten onto Paddler's tail. With Mr. and Mrs. Beaver absent at first, Roz enters the shallows, extends a fallen branch, and lifts Paddler from the water. Roz then catches Rockmouth while Paddler drops safely back into the pond and the beavers arrive.

Mrs. Beaver is furious and wants Roz to throw Rockmouth to the vultures, but Roz refuses to harm the fish. Instead, Roz places Rockmouth in a deep puddle where the fish cannot escape and waits until Rockmouth explains himself.

Roz discovers that Rockmouth once lived in the river, but the beavers' dam trapped Rockmouth in the pond. Mr. and Mrs. Beaver remain angry about the attack on Paddler, but Paddler sympathizes with Rockmouth, recognizing how terrible it would feel to be separated from home.

Roz decides to return Rockmouth to the river. After scouting the waterways, Roz realizes the only solution is to carry Rockmouth through the forest and across the Great Meadow, so Roz asks the beavers to help make a water-filled container.

Mrs. Beaver eventually overcomes her anger and admits the beavers share some blame. The beavers carve a wooden barrel, Roz fills it with water and Rockmouth, and Roz carries the fish to the riverbank. When Roz tips Rockmouth into the river, Rockmouth smiles and swims away, finally back home.