Hardie's attempt to help a stranded man goes awry when he realizes that man has a $25,000 bounty on him.
Mike Nelson cruises to a small Mexican fishing village where he finds strange phenomena. Every fish in the vicinity seems to have disappeared. Mike uses the latest scientific 'miracles' to pierce the mystery of the disappearing fish.
Mike Nelson learns of a derelict mine that has drifted into the harbor of a nearby town. The town's principal industry, a nitrate factory, will blow up and destroy the city if the mine explodes.
