A ship sent to investigate a wave of mysterious sinkings encounters the advanced submarine, the Nautilus, commanded by Captain Nemo.

Captain Nemo (José Ferrer) is found in suspended animation under the sea and revived by modern-day Navy men in order to battle a fiendish mad scientist (Burgess Meredith).

A chance discovery leads American mining engineer Ben Harris and acquaintance Harold to discover a lost city under the sea while searching for their kidnapped friend Jill. Held captive in the underwater city by the tyrannical Captain (Vincent Price), and his crew of former smugglers, the three plot to escape...

Some survivors of a drowning ship are rescued by Captain Nemo and his submarine crew. They are taken to an underwater city, where they may be trapped for the rest of their lives.

When an underwater ocean lab is lost in a earthquake, an advanced submarine is sent down to find it and encounters terrible danger.