Set just after the American civil war, businessman and inventor Victor Barbicane invents a new source of power called Power X. He plans to use it to power rockets, and to show its potential he plans to send a projectile to the moon. Joining him for the trip are his assistant Ben Sharpe, Barbicane's arch-rival Stuyvesant Nicholl, and Nicholl's daughter Virginia. Nicholl believes that Power X goes against the will of God and sabotages the projectile so that they cannot return to earth, setting up a suspenseful finale as they battle to repair the projectile.

Two 19th-century sailors jump ship only to discover their tropical paradise is a cannibal stronghold.