Seven thousand meters below the ocean's surface, the crew of the BathyTech 3 mineral mining facility has found something remarkable: a rock-like sphere of unknown material and origin.

For Mo Rees, the discovery calls to his inner explorer and adds color to his dull miner's life. Even better than the promise of new knowledge is the unexpected connection he forges with Dr. Armin Savage-Hall, leader of the team brought down to study the thing.

For Armin, the object is the find of a lifetime. It could prove his controversial theories and secure his scientific reputation. And Mo is a fascinating bonus.

Then crew members start behaving strangely. Worse, they start to change: their eyes glow purple, their teeth sharpen. Then the violence begins, the brutal deaths. As BathyTech descends deeper into chaos, the surviving crew works desperately to find the cause of the horrors around them. What they uncover could annihilate the human race. And they can't stop it.