Tolbiac (Cornillac) wakes up naked, disorientated and lost in a dark cave deep below ground. He's cold, hurt, and has no idea what brought him there, or what happened to the dead man lying next to him. Surrounded by the ruins of an underground world and with only the faintest light source to guide him, Tolbiac attempts to recover his lost memory as he struggles to reach the surface. His journey takes him through a labyrinthine network of tunnels and abandoned laboratories, where he discovers he is not the only one trapped in this tomb-like underworld. Pursued by ravenous mutants and evil phantoms, he eventually meets a woman who may provide the clue to his identity, while all along the way he is confronted by evidence of a mysterious organisation known as Eden Log.
