Moomin Troll finds a dragon in the river, and tries to keep him a secret from everyone, while training him to show to Snuffkin.

When a great flood fills the valley, the Moomins find somewhere new to live - a floating theatre! But is somebody already living there?

Moominpappa is inspired to put on a play all about his own adventurous youth. But the pressure to fill his father's shoes makes Moomintroll's tail hairs fall out, and his mother's medicine has some rather surprising side effects!