'Some say the world will end in fire.

Some say in ice...'—Robert Frost

Alexa Glock is teetering on a precipice, the ground threatening to open up beneath her—and it's not just the immediate peril of retrieving a long–lost hiker's skull, given up by a melting and dangerous glacier. She's spending a ski weekend with boyfriend DI Bruce Horne and his two daughters, and she couldn't be more terrified. An entire weekend trying to win over a sullen teenager and a preteen with obvious loyalties to Mom? She's more comfortable almost sliding to her death on an unstable glacier. When she indeed finds herself dangling in a crevasse waiting for the experts to rescue her, she discovers a pelvis (wearing a red Speedo!) frozen in the ice, and the heartbreaking task of identifying multiple remains and bringing closure to families begins.

Once safely back on terra firma, awaiting the arrival of Bruce and his dreaded daughters, Alexa follows the smell of smoke to a nearby pizza joint which has been completely destroyed by fire. When a body is discovered in the smoldering ruins, Alexa splits her time between fire and ice, working to identify a family's long–lost loved one and the charred remains of the fire victim. Then an avalanche during a snowboard competition leaves Bruce's oldest daughter missing along with the snowboarder she's been hanging out with. As Bruce and other rescuers race to find the missing teens, evidence begins to suggest that neither the fire nor the avalanche were accidents, and that the daughter's boyfriend might have information about both...