Patriarch Steve Preston goes missing and worried mom Emma (Ida Lupino) sends eldest son Mark (William Shatner) in search of his father. Suddenly, a dying, eyeless Steve returns and demands that the family: “Give Corbis what belongs to him!” before dissolving into a gelatinous meltdown.

Corbis (Ernest Borgnine) is a Satanic priest hell-bent on recovering a valuable book listing the names of those who sold their souls to the devil…a book that resides with the Preston family. Mark refuses to hand it over and puts up a brave fight, only to wind up an unwilling sacrifice.

Occult expert, Dr. Richards (Eddie Albert) and Mark’s younger brother, Tom (Tom Skerritt) plot to free the Prestons and destroy The Devil's Rain, a bottle containing the souls of those already damned. The battle rages as the elixir is released and a bloody rain of devilry and malevolence is loosed upon a screaming, melting world.