Inspector Capell and Lonergan, a former police officer turned novelist, are currently looking into a horrifying murder spree that has been going on. It was discovered that the murders were the result of a genetic engineering experiment that had gone out of hand. In order to eradicate the horrifying miscreation, the two guys will have to go into the sewer networks of the metropolis. It won't be difficult to track it down, as it is already on the lookout for its subsequent victims...