Cambridge, 1354. Christmas approaches and the town is gripped by the worst blizzards in living memory. The weather has trapped many travellers in the town, including Matthew's erstwhile love, Philippa. She and her wealthy husband are invited to Michaelhouse for the main feast, and Matthew is horrified that he does not immediately recognise the woman who once stole his heart. He is relieved to accept Brother Michael's orders to identify a man found dead, apparently from exposure, in a nearby church. The success of his mission brings him closer to Philippa's circle, for the man was her husband's servant. And then the husband himself is found dead, victim of an accident on the treacherous ice of the fens – or something more sinister?