A murderous hamadryas baboon, Typhoon, escapes from a laboratory and wreaks havoc on a group of teenagers playing a Dungeons-and-Dragons type game in a research building. The animal was driven insane by an experimental drug administered by Professor Sorensen (Roddy McDowall). As the carnage unfolds, medical student Sam (Christopher Atkins) must confront his own survival instincts to outsmart Shakma and ultimately meet a tragic end.