Kemlo and his friend Krillie, who have set out from Satellite Belt K on a Space trip, find themselves off course and eventually land upon a planet about which very little is known except that odd things happen there, so that it has become known as the Crazy Planet.

The people upon it, whose language is laughter, are friendly; but others, from Earth, are also marooned upon it, and they are very far from friendly, not only to the laughing People but to Kemlo and Krillie too. Their wicked plans, however, are foiled by Kemlo, who is later responsible for helping his new friends against a mass attack of the murderous wood beasts...