Tom is a 12-year-old orphan living in
York in the mid-19th century. He is taken under the wing of Grimes, a roguish
chimney sweep, as he is small enough to climb inside the chimneys. One day, they leave town and go to Harthover Hall, a huge country house set in vast grounds. Grimes rides a donkey – Tom and Grimes' assistant Masterman walk alongside. At the house, Tom gets lost in the maze of chimneys and appears in a young girl's bedroom (Elly). Meanwhile, Grimes is passing silverware out of the windows to Masterman. When discovered by the housekeeper, Grimes blames the crime on Tom who makes a run for it with his dog Toby. They are pursued across the estate, and end up at Dead Man's Pool: a deep pool in a fast flowing river. Although the young girl protests his innocence, Tom jumps in with the dog. The film then switches to a fantasy animation of speaking sea-creatures. Here he must help rescue his new friends, the Water Babies, from enslavement by sharks. This section includes multiple musical sequences mainly involving Jock the Scottish
lobster, Terence the English
seahorse and Claude the French
swordfish. The story jumps to a cave in
Antarctica where they join forces with Cyril the
Walrus, a group of
polar bears, and a flock of penguins; and also encounter the sea king Kraken also known to many as
Neptune and
Poseidon. In the end, Kraken returns Tom and Toby to their world for
self-sacrificing for others instead of choosing their own needs. On their world, Tom proves his innocence and helps capture Grimes. He is then adopted by Elly's family. ==Cast==