Mr Beam, the lighthouse keeper, is in trouble! His lighthouse lamp has gone out and he cannot get in to relight it because ha has dropped his door key in the sea. Meanwhile, a ship is heading for the rocks? Here's a job for the Diddly's! Join the steam-powered superheroes as they battle to help Mr Beam, meeting a pretty mermaid and pitting their wits against a bad-tempered whale along the way. Will they be in time to prevent a disaster?
