As the series progresses his reputation improves with his superior, Detective Inspector (DI) Aspinall, who realises that Davies' intelligence and fair but determined methods make him the best policeman in his squad.

A strained mutual respect develops between the two characters as Davies increasingly finds the time to try to understand the troubled, hard drinking DI and his history (and demons).

The other major aspect of the series concerns Davies' private life, which centres on his estranged wife, Julie (played by Emma Amos).

The storyline regularly integrates Davies' attempts to address the loss of his wife's respect and to repair the damage done to their marriage after his career stalls in the Metropolitan Police Force; for instance, the estranged character returns to pick up a dog whose custody he shares with Julie in the first episode, serve as her occasional chauffeur and carry out routine household maintenance at the family home (occasionally intersecting with Julie's new relationship interests).

His work and personal life intertwine in interactions with his friend, the irreverent and rather feckless Mod (short for Modesty) Lewis, played by the Irish comedian Sean Hughes, which include their park bench talks about cases and life, Davies' chauffeuring the unlicensed Mod, and Davies' walking his dog—an unnamed, but consistent character, a Landseer in early episodes, and later a St Bernard.