Few have ever seen the incomprehensible entities known as Trench Dwellers, but their lethal biomechanical machines remain, guardians of a long-forgotten empire.

In the dawning of time, a mighty civilization, mystical and alien, flourished in the oceanâ??s unseen depths. Their day has passed, but their hidden metropoli linger on.

Legends even to the merfolk, the reclusive Trench Dwellers are a race alien and strange beyond human reckoning.