Mike has been hired to test a machine dubbed "the fish-finder" on an experimental boat called The Sonar Queen, in hopes of determining why all of the fish have disappeared from the coast of a Mexican fishing village.
Mike Nelson has been hired to test a new relatively inexpensive sonar device that can be used as a fish finder. After a day of testing they dock in a small Mexican village where an old fisherman is being beaten. It seems the old man is catching plenty of fish while the other fisherman are returning practically empty handed. He's refusing to tell them where this fishing spot is located and some are accusing him of witchcraft. Mike steps in not only to protect the old man but to find out why the fish seem to be congregating in one particular location. Written by