Oslo the whale lives with his dad. He likes swimming, blowing water out of his blowhole, and eating krill and ketchup.

Oslo is the only whale he knows whose tail looks a bit like a wellington boot. Not that it matters, but then again, Oslo's tail seems to be at the root of all kinds of unexpected events.

Along the way, Oslo learns about a lot of things: goals, opposites, sharing, fairness and panic. But will his big moment end in catastrophe? Or might there be a joyous celebration?