In the winter of 1594, the body of a young woman is found washed up beside the Thames. She has been cruelly mutilated, and cannot be identified. Meanwhile, Thomas the Falconer arrives in frost-bound London on a sensitive mission: to persuade his master Sir Robert to give up his foolish infatuation with a notorious Lady of the Court. But the Lady Imogen's intrigues are more sinister than even Thomas imagines - and soon he is caught up in a bizarre spiral of events. Thomas's friend Ben Mallam, the streetwise jingler (a dealer in used horses) returns to aid him. After a run of bad luck, perhaps Ben's fortunes will change as he helps Thomas unravel a deadly plot which strikes at the very heart of Tudor England, threatening the security of the nation itself...