Young J. Quincy Pennant is a brilliant but absent-minded scientist who is experimenting with an explosive method which directs a shock wave past obstructions to impact a distant target.

He is sent to a rapidly growing "powder town" being developed around an arsenal and munitions factory where population growth has attracted criminals, foreign spies and saboteurs.

Pennant is placed in a boarding house where he is the only male sharing with five female entertainers who work at a local casino run by gangsters.

The rambunctious and physically imposing Jeems O'Shea, head of the powder monkeys at the factory, and his sycophant Billy arrive at the house.

They attempt to blow up the factory and set a 5-minute timer with explosives on a cart inside the dynamite room after they bind O'Shea and Pennant.