It's been eighteen years since Mary Kelly vanished from a snowy hillside in Boston. It was Darby McCormick's first case. It was her first failure.

At long last the prime suspect - disgraced priest Richard Byrne - has agreed to break his silence. But he'll only talk to her.

Darby returns home expecting to hear a confession. What Byrne tells her is far more disturbing.

And she doesn't have long to act, because it soon becomes clear that someone will do anything to keep this cold case on ice . . .