Hathaway's murder theory has fallen apart. It might take Lewis's insight to close the case - but will his former protege listen?

When a classics scholar is stabbed to death and dumped in the Oxford Canal, Lewis, Hathaway and Maddox find themselves sorely tested by a bizarre case.

After a difficult start, Lewis and Hathaway's partnership seems to have gained some semblance of normality. DS Maddox has become a part of the team. Her abilities will be put to the test when an investigation begins on the brutal murder of an American classics student Rose Anderson Her body is hauled from the canal with a stand wound to the neck and abdomen. Suspicious soon fall on astrophysics professor, Felix Garwood who had recently broken off an affair with Rose. However, Felix was married to Rose's supervisor, Philippa Garwood. Could the jealous wife have committed such a murder?

Lewis' reputation is jeopardized when the very first case that he solved as a DI is reopened for appeal and new murders are committed with the original weapon.

Hathaway and Maddox continue to investigate the murder of Travis as the trail leads back to Lewis’s original case. The two detectives attempt to prevent another murder and Lewis sees himself isolated and alone with his reputation in jeopardy.