With her career in tatters and her marriage receding in the rear-view mirror, ex-RCMP corporal Lacey McCrae trades her uniform for a tool belt, and the Lower Mainland for the foothills west of Calgary. Amid the oil barons, hockey stars, and other high rollers who inhabit the wilderness playground is her old university roommate, Dee Phillips. Dee’s glossy life was shaken by a reckless driver; now she’s haunted by a nighttime prowler only she can hear.

As snowmelt swells the icy river, threatening the only bridge back to civilization, Lacey must make the call: assume Dee’s in danger and get her out or decide the prowler is imaginary and stay, cut off from help if the bridge is swept away.