Britt Reid, newspaper publisher, is waging war against the racketeers. Masked as the Green Hornet he hunts the biggest of all game-public enemies that even the G-men cannot reach. With his faithful valet, Kato, he visits a tunnel being constructed under the river with faulty material and equipment. Forcing the foreman into an air lock, with an ingenious gas-gun he is ordering him to name the higher-ups in the construction racket, when an air compressor fails, and water comes rushing in! Will our heroes escape in time?
