Warden Guddy, the overseer of Earth's prison, hypnotizes a rocket pilot named Mack to crash his rocketship carrying a cargo of radium bullion headed to Mercury. Thereafter, Max Guddy uses hypnotized prisoners to gather the boxes of bullion. Dr. Carter is informed that his son Bob Carter, Secretary of the Earth Bankm is behind some of the activity. Bob confesses under hypnotized state Guddy placed him under, which puts Bob's sister Gloria Carter in great distress.
Dan Hastings investigates by hiding on one of the space freighters. When the pilot is compelled to crash it, the lieutenant parachutes out. He observes as Guddy's prisoners collect it. Recognizing one of the prisoners, Pietro the Mugger, he informs Dr. Carter. Dan returns with Pietro to take a lie detector test, which Pietro passes with flying colors. The doctor surmises that Pietro may have been hypnotized.
Dan makes an excuse to have his eyes checked at R.B. Crane Eye Specialist. Dr. Carter leaves the lieutenant for the examination. Hastings confronts Warden Guddy with a pair of "smoked contact lenses" so he could not be hypnotized. The police are waiting outside, and hear Guddy's inadvertent confession.