The legendary Sargasso Sea and Devil's Triangle disclose new mysteries as Tom Swift searches for a pirated space probe bearing a priceless payload--cometary matter from the dawn of our solar system. The quest takes an eerie turn when Tom's new detection device reveals an inexplicable gravitational anomaly that may be a fantastic seacraft a half-mile wide! To pursue the undersea search in the jngles of Sargasso weed, the young inventor must perfect...