Shemp has to get married within seven hours in order to inherit $500,000. Now that's incentive! The bumbling threesome set to work right away with hilarious results.

Set in the stone age, the stooges are cavemen who must have various misadventures hunting, gathering, and otherwise coping with prehistoric life. When some other cavemen threaten to take their women ("Aggie", "Maggie", and "Baggy"), the boys fight them off with a catapulting tree branch that shoots rocks and eggs.

To inherit a fortune, voice teacher Shemp must marry before six o'clock, but no girl will accept his proposal. Finally one of his repulsive students agrees to marry him, just in the nick of time. When the rest of the prospective brides hear about the inheritance, they show up at the ceremony and a free for all ensues. Shemp marries his student before the deadline, and then finds out that there is no inheritance. Moe and Larry have tricked him into marriage as revenge for their marrying his shrewish sisters.

The stooges hope to collect a reward by proving to a museum that cavemen still exist. They return from their expedition with a film purporting to show some stone age stooges defending their women from other cavemen. The museum curators are about to pay they reward, until they overhear the stooges talking about how they faked the film, with themselves playing the cavemen.

Harry tries to entertain a family of rich hillbillies.