San Francisco narcotics cop William Holley has Walter Matheson under surveillance, waiting for the cocaine dealer to make an error on one of his smuggling runs across the Canadian border. He plans an arrest when Matheson hires a light aircraft to run a key shipment over the Cascade mountains into Washington State. But the plane crashes and Matheson turns up a week later in San Francisco denying all knowledge of the affair.

Climbers Alex Townsend and Gordon Wilson are drawn into the mystery and as police and the criminals close in, Alex, Gordon and Alex's girlfriend Linda are trapped in an uncontrollable vortex of guilt, beyond their control.

David Harris unfolds his story with economy and drive, positioning and characters in cunning juxtaposition in a tense story set against the cities and mountains of western America and Canada. The book first appeared in the omnibus One Step in the Clouds and received instant acclaim.