After Jimmy Olsen (Jack Larson) is given a $1 million reward for rescuing an eccentric woman’s cat, he and Lois Lane (Noel Neill) are locked in a vault-like room by hoodlums, led by Herbert, a con man Jimmy hired to be his butler. The room is lined with lead, so they cannot be seen by Superman (George Reeves). Jimmy and Lois are running out of air. The room, however, has a handy exhaust duct—no supply, only exhaust. The duct goes straight to the roof, although it does not have a fan. Even better, the duct is controlled by a manual damper on a string. Jimmy and Lois’ only chance is to burn Jimmy’s money and use the damper to spell out “SOS” in Morse code. Superman sees the smoke signal and comes to the rescue, and Jimmy is a penniless cub reporter again. HVAC saves the day!