In the depths of the Atlantic Ocean, the Orpheus' team of scientists are on a mission to find a renewable source of energy.

The scientific crew on the Orpheus submarine run into severe danger in their quest to find rare micro-organisms. One crew member has died, the Orpheus has been intercepted and two of the crew are trapped and running out of air.

The Orpheus crew's quest for renewable energy has led them into danger. They're trapped on Volos, a Russian submarine, and its nuclear reactor is dangerously overheating.

The captain of the Orpheus wants to find out more about the rare bio-fuel samples. However, the Russian captain has other ideas.

The Orpheus crew have found rare bio fuels in the ocean depths, but they must find a way of getting it to the surface safely.