Native American lore infuses a southwestern mystery featuring the indomitable Rachel Murdock and her cat, Samantha.

The notes—short and sharp—seem to strike at the heart of each recipient's insecurities and darkest secrets. Signed "Kachina," they've been sent to a group of friends who met in college, including Rachel Murdock's goddaughter, Gail. When Gail wants to unmask the letter writer by inviting the group to her house in Arizona, she asks Rachel for help. Unable to resist, Rachel scoops up her cat, leaving her sister behind on a tour through the Southwest.

As the seven friends reconnect, familiar grievances and new resentments emerge. And when one woman—as prickly as the cacti dotting the desert landscape—is killed by a rattlesnake bite, the party takes an even darker turn. A thunderous storm soon washes out the roads, and the group is left on their own with a dead body and a murderer in their midst. Now Rachel must use...