Two escaped convicts are found hiding in a rocket ship built by a renegade inventor, who forces them to become the crew for a trip to the Moon. Also on board, as inadvertent stowaways, are his assistant and his secretary; and none of them are aware that the inventor is actually a Lunarian explorer sent to Earth by the dying Lunar civilization.

Herman (a mouse) and Henry (a rooster) notice a poster that will award $1,000 to anyone who will stay in the ring for one round against a champion boxing rooster. Herman goes to Henry, who is feeling really low about himself, as he is getting bossed and pushed around by his wife. One thing leads to another, and the scrawny Henry is going up against the Champ.