Find out why Lewis rejoins the force after his retirement.

Hathaway gets to work on his first case as an inspector, with the help of his new partner, DS Lizzie Maddox. The crime is a complicated one that bridges the worlds of neurosurgery, blood sports and animal rights. Lewis, struggling to adapt to retired life, jumps at the chance to rejoin the force when Superintendent Innocent seeks his help. With Lewis back on the team, will they be able to solve the mystery?