He was suspect number one--the man who tried to kill Deputy Mattie Cobb and may have killed her father thirty years earlier. But when Mattie and cold case detective Jim Hauck reach the Colorado state prison where they will finally get to interview him, he's found dead in his cell. There's only one clue: a map leading to Timber Creek and rugged Redstone Ridge.

Though she usually works with veterinarian Cole Walker, Mattie's K-9 partner Robo has just sired a litter of pups, who require special, time-consuming care at Cole's clinic. Left to explore the map's clue without him, Mattie and Robo journey into the burned forest surrounding Redstone Ridge. But before they can finish their search they're called to help investigate the death of a young woman found in a campground filled with elk hunters. Identification of the deceased points to her having recently given birth, but the infant is nowhere to be found.

As a deadly storm descends upon the mountains, covering everything with a layer of ice and snow, Mattie and her team search for the missing newborn. The storm batters the area, taking its toll on the team and forcing the sheriff to call in reinforcements. When new evidence surfaces, they decide that finding the woman's killer will lead them to her baby, making them even more desperate to solve the case.

Then Cole goes missing, stranded alone in the high country with a person that Mattie now suspects is the mastermind behind several murders, including her father's. She and Robo take to the trail to find Cole--but the killer has a cold-blooded plan that threatens them all.