In his unique invention the Ocean Arrow, an “under-water helicopter,” Tom Swift Jr. embarks on a precarious search for a lost rocket from space.
The rocket, containing evidence of living things on an-other planet, was directed to Swift Enterprise’s for scientific study. But its course was mysteriously changed while the rocket was hurtling toward earth—and its landing site is un-known!
Tom suspects that the rocket lies underwater, some-where off the coast of South America. Accompanied by his friends, Bud Barclay and Chow Winkler, and two expert oceanographers, the young inventor sets out in his diving seacopter to locate the rocket.
But a group of unethical scientists have uncovered a clue to this valuable treasure from space. In their own un-dersea craft, they try to thwart Tom in his attempt to claim the rocket which rightfully belongs to Swift Enterprises.
Unexpected dangers confront the Swift expedition every mile of the search for the scientific prize. When, the Ocean Arrow is trapped in a crushing, underwater landslide, Tom and his companions nearly lose their lives. How they overcome sub-ocean hazards, as well as their cunning ene-mies, makes one of the most exciting stories to elate in the TOM SWIFT JR. series.