Professor McQuatness invents a formula pill that re-arranges the electrons of the human body, allowing a person to travel in time. When the Professor persuades a skeptical Flash to travel back to 50 B.C., Joan Williams and several crooks make the journey as well.; The Flash loses his super speed and becomes a galley slave for Julius Caesar, while the crooks, armed with machine guns, join with the Egyptians to battle the Roman legions.; Having regained his speed and saving Caesar's soldiers from certain death, the Flash is besieged by Roman citizens to help them regain their freedom from Caesar's tyranny. At the same time, Brutus (sworn enemy of Caesar) conspires with the future criminals to dispose of Caesar once and for all, including the Flash!; Having rediscovered his time pill formula, the Professor and all the principals make their way back to 1942. However, the crooks find out that the Professor has left some very valuable items in a time capsule back in the Rome of 50 B.C., so they kidnap the Professor and Joan, traveling to the present day Rome to see of they can find that time capsule.