Hy Pressure was a strong-arm agent who worked for the underworld group, the Apparatus. When introduced, Pressure was assigned the job of “pressuring” local farmers into selling the mineral rights to their farms for a pipeline consortium. Pressure approached dairy farmer George Wheaton to buyout his land and Mr. Wheaton refused until Pressure mentioned a shooting accident might befall his daughter Nellie.
Lucky for the Wheaton household, they were taking care of an amnesic Sparkle Plenty and hiding Mysta Chimera. When the ladies were found and the trouble on the farm revealed, Dick Tracy planned a sting operation to capture Hy Pressure. During a terrible storm, Pressure approached the Wheaton household where Tracy presented his badge. The power went out at that exact moment however, and Pressure escaped in the dark. Finding Sparkle and Nellie he pointed his weapon at the girls, intending to take hostages. Instead Mysta zapped him near to death with her Lunarian powers.
Outside the farm members of the Apparatus Enforcement crew and the upstart criminal group the Consortium traded gunfire and Pressure escaped out of the farm-house in the confusion. He met a wet and frusterated Doubleup, who had come to collect Hy Pressure and the deed to the farm. When Pressure admitted he hadn’t forced the sale, Doubleup snapped Hy’s neck with his whip.