Jim Brandon, the famous biochemist, with Fern Collier is his assistant who is the sole person to know his identity as the Avenger.
Scrawny, and Pedro are two thugs who settle accounts, but will there be a double crossed? Brandon describes the power of his invisibility capsules to his side kick, when a psychic flash of sounds hits Brandon. What does it mean?
On the job, Brandon investigates the latest crime scene in his capacity of forensics sciences. He tries to teach his companion, Fern some of his technique. Brandon is sure his psychic flashes are linked to the crimes with jewelers. He and Fern discuss the details of the open cases. Trying to warn the next jeweler, Brandon’s instincts lead him to Skrawny. Fern helps send the trail to a sea faring man known as Captain Peabody. Will he be able to shed light on knowing how long the bodies that had been found were in the water?
As Brandon tracks down his man, Fern is left behind to be captured by Scrawny. Too bad the thug is easy work for the invisibility power of the Avenger. In a final scene, Brandon clears up the loose ends with the police.