The sole survivor of an Army plane crash in the Peruvian hinterlands, Jim Ellison subsisted for nearly two years on his raw animal instincts. When he returned to America and became a police lieutenant, Jim discovered that the abilities that had kept him alive in the jungle now gave him extraordinary senses of perception. With the help of Captain Simon Banks and a grad student Blair Sandburg, Jim now attempts to use these powers to apprehend a terrorist bomber called the Switchman.