For nearly two months, the USS Newark, carrying an experimental, top-secret military cargo, has been lost at sea.
When the sub is finally discovered sixty miles off the coast of California, the government, eager to regain the lost cargo, assembles a highly-accomplished salvage team, accompanied by Dr. Carly Ryan - head of the original project - and her assistant. Unaware of the danger lurking within the sub, the team is sent in to recover the cargo and determine the cause of the ship's disappearance.
Their search quickly reveals that most of the sub's original crew is dead – mutilated and dismembered – and that there is a low-level radiation leak emitting from the ship's reactor. A single sailor, however, is found alive, driven insane by his time at sea trapped upon the damned Newark. His half-mad tale of carnage and monstrosities is substantiated as members of the recovery team begin to fall to the terrifying dwellers of the stranded sub. Subjected to tortuous interrogation by the crew, Dr. Ryan reluctantly discloses the startling secret of Project: Tiamat (named for the Babylonian Goddess that gave birth to scorpion warriors): several scorpions were genetically enhanced into an exceptionally adaptive form of biological warfare.
With this startling revelation, the rescued seaman and the remaining members of the recovery crew must overcome a seemingly inexhaustible number of scorpions, which have been further mutated by the ship's leaking radiation. Through it all, a strange rash on Seaman Thompson's back unnerves Dr. Ryan. The mutation process has begun . . .