Animal rights protesters free four monkeys from a research laboratory one of which is infected with the deadly marbury virus.

When members of two feuding families decide to settle their differences with an old-fashioned duel, Jim ends up with a murder to investigate.

Employed to look into companies seeking trade licences in Jersey, Bergerac finds more than he expects. Danielle is convinced that his life is in danger but nobody will believe her.

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.