An urgent phone call from newspaper reporter, Lawery, comes in to Brit Reed about cracks forming in the dam at the resevoir. If the dam breaks, the valley could be flooded, and lives at risk of drowning. The secret of why the wall caved in is discovered, and Lawery rushes to Brit with proof that it was no accident.
Why would someone purposely sabotage the dam? Listeners are privvy to gangster plans to use the catastrophy to cover up their tracks. Smelling the rats, the Green Hornet sets out to learn what he can about the happenings at the resevoir. The Hornet phones the racketeers to blackmail them, claiming he’ll keep their secret for a payoff.
The crooks are at it again when a senator is threatened. Will they sabotage the dam again to cover their tracks? Even the Green Hornet sees this as a matter of great importance for the police. Still, our hero has a plan to give the racketeers a taste of their own medicine. How will the bad guys feel if they were at risk of drowning at the result of their own work?
Headlines in the newspaper scream the sensational conclusion.