Your Move. Carol Golden, #7

Somebody is killing people who work for subsidiaries of conglomerate Ault Enterprises and playing some kind of game while doing it. Carol Golden is called on to help identify the killer because she has experience in breaking codes and playing games. Amy O'Connor, a former scam artist and long-distance hiker with an eye for men, becomes her partner by accident, and together they search for clues in interesting places.
The hunt takes them to the tops of significant mountain peaks in the United States, including Mount Whitney, the highest peak in the continental U. S., and to other unusual locales such as the thinly populated Lost Coast region of northern California. Carol finds that incidents in her past that are lost to her because of her amnesia may come back to haunt her before she can win this deadly game.