A secret agent possesses a ring that makes him invisible for a short time, once every 10 hours. He is in pursuit of an evil criminal mastermind but, at the same time, must evade an enemy agent who also wants the ring.

"THIS WOMAN is the most thrilling act of espionage you've ever seen! She holds the key to "Matchless" - a spy plot as flawless as her beauty - as reckless as her body!"