A new conference center has been constructed despite warnings by biologist Dr. Connelly that the grounds are toxic. At the center's 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. 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, Douglas Middleton, a priest attending the conference, joins security chief Mr. Deadmarsh in evacuating guests. As the panic spreads, so does the slime - a pulsating, dripping, moving, inescapable, ecological disaster that is awakening everyone's worst nightmares.