With the arrival of spring and fine weather outside, the good-natured Mole loses patience with spring cleaning. He has fled his underground home and ends up at the river, which he has never seen before. Here he meets Rat, a water vole, who takes Mole for a ride in his rowing boat. They get along well and spend many more days boating, with "Ratty" teaching Mole the ways of the river, with the two friends living together in Ratty's riverside home. One summer day, Rat and Mole disembark near the grand Toad Hall and pay a visit to Toad. Toad is rich, jovial, friendly and kindhearted, but aimless and conceited; he regularly becomes obsessed with current fads, only to abandon them abruptly. His current craze is his horse-drawn caravan. When a passing car scares his horse and causes the caravan to overturn into a ditch, Toad's craze for caravan travel is immediately replaced by an obsession with motorcars...