Jim Bergerac is a recovering alcoholic, divorcee and father of a young daughter. He is a detective sergeant with the Bureau des Étrangers, a department for non-residents in Jersey, Channel Islands. Jim likes doing things his own way, a true maverick, and consequently doesn't always carry out his investigations in the traditional manner, the way his boss, Barney Crozier, would have preferred. But Jim's winsome grin and chirpy optimism always win through, and in a way he still manages to remain on fairly good terms with Crozier despite their differences. Jim gets his fair share of women during the series, but more than anything else he is married to his job, which becomes increasingly difficult for some of them. In the later series Bergerac leaves the police to become a private investigator.
Charlie recommends that Jim be hired to protect a priceless set of sixteen Chinese figures called Lohans. Despite Jim's vigilance they are stolen and as he investigates their true ownership is brought into question.
The mysterious Hapgood invites Bergerac to a lonely castle in Brittany. He wishes to hire Bergerac as a bodyguard and also to investigate threats on his life. Full recap: When someone fires a volley of shots at them whilst Hapgood is out painting, the result is the termination of Bergerac's services. Undaunted Jim continues his own investigation and via some gossip from Charlie, he forces Hapgood to admit the truth. He is a former assassin who has ""turned his back on the game."" He is being targeted by his replacement, who wishes to remove him from the game permanently. Hapgood hopes to persuade the assassin to follow his lead and see the light. Late at night the assassin attacks but Hapgood inadvertently kills him during a struggle. When the police arrive the next morning, Hapgood is haunted by Bergerac's earlier words, that he will never know who the next assassin will be.
An eccentric old lady's mysterious past is somehow tied to a sunken ship that has attracted many divers, including a world-renowned underwater archaeologist and a notorious gangster.