The "boomerang box" is a high-tech computer program designed to save an aircraft experiencing flight trouble, and Dr Ben Coles looks upon it as his baby. But, after a test run over the Gulf of Alaska goes awry, he suspects someone may have sabotaged the plane's computer systems. And, mysteriously, April Rosen is horrified to learn that almost simultaneously her father's amphibian Albatross has narrowly escaped a mid-air collision over the same patch of sea.

While Dr Coles considers the uncomfortable notion that someone within his own company might wish him harm, April begins her search for the cause of her father's chilling near-miss. But what they don't know is that their fears have a common source. And meanwhile they are being watched by people in the Pentagon who fear that the two may stumble on a secret that will destroy them all before Skyhook has a chance to succeed. But what is Skyhook's real purpose?

'Nance knows how to build suspense...with plenty of aerospace jargon and heroic stunts' BOOKLIST