The Chinese have developed a way to turn a human body into an intense bomb. They intend to infiltrate the Soviet Union and create a diplomatic incident that will draw the US and Soviets in nuclear annihilation.

Cybernetic genius Tabor Ulrich creates a perfect mechanical duplicate of Admiral Nelson. His plot: to make the crew of the Seaview think they are fighting World War Three. In doing so, the sub will launch nuclear missiles at the China, Russia and the USA. After the holocaust, Ulrich plans to take over and usher in "the age of the cyborg".