Trevor, an insomniac lathe operator, experiences unusual occurrences at work and home. A strange man follows him everywhere, but no one else seems to notice him.

A scientist develops a formula which will cause animals to regress to the form of their primitive ancestors, and tries it on himself with disastrous results.

A killer called ‘The Dark Man’ commits double murder. This is witnessed by the young aspiring actress Molly Lester. The Dark Man tries everything to put Molly out of the…