Television experimenter Curtis Drew sets out to combine the X-ray with television to aid surgery. However, he discovers instead 'pure' television - invisible 'Z-rays' which have the potential to receive and record any situation - anywhere. Nothing is private any more. Immoral acts, and hidden crimes can all be exposed. The 'Z-ray' could benefit humanity, yet to Drew it opens up more lucrative possibilities. He becomes a scientific 'Peeping Tom' and blackmailer, but when murder results, Scotland Yard becomes interested...