A conference center has gone up despite warnings by biologist Dr. Connelly that the grounds are toxic. At its inaugural Clean Planet conference, one of the delegates is found dead, his face frozen in fear. Adding to the odd disturbances is a mysterious oily black slime oozing its way around the conference site. Soon the guests start complaining to conference coordinator Khali, who becomes a fast believer in the strange events after being accosted by a rogue German Shepherd. It's not just any snarling canine. It's the very same one that attacked her when she was just a child. But how can that be? It's soon discovered that the slime amassing on the lake front, clogging drains, seeping into rooms, and sliding along halls is a massive cellular organism living in the sewer system—highly intelligent, and capable of inducing fearful hallucinations in its victims. When the truth is revealed to Khali and Douglas Middleton, a priest attending the conference, they join security chief Mr. Deadmarsh in evacuating guests. As the panic spreads, so does the slime—pulsating, dripping, moving, and awakening everyone's worst nightmares.