Sam Wintripp, a half Tilok Native American espionage expert, must foil a double plot to unleash a deadly brain-altering genetic vector into U.S. cities and a potent electronic virus into the world's interconnected computer systems.

A powerful and potentially dangerous form of biotechnology has fallen into the hands of a terrorist mastermind. With it he plans to use microscopic vector particles developed originally for therapeutic purposes to make genetic modifications in humans on a large scale. The unlucky victims become senselessly violent until they die 48 hours later. Sam fears that the simultaneous outbreak of random violence and a massive attack on essential US computer systems will destabilize financial markets, a circumstance that will allow anyone with advance knowledge to make huge profits.

A crack team of high-tech experts tracks the plots' mastermind through cyberspace while Sam pursues him across the continent. The fate of millions of people depends upon their success.

Unacceptable Risk is the second Sam Wintripp novel, following Overfall.