The Honourable Man (S06E05)

After the passing of a family member, Sgt. Wilson receives an unexpected inheritance: a noble title. Meanwhile, a Russian factory worker comes to town to foster better Anglo-Russian relations, leading to Mainwaring being chosen to present the key to the town. However, things take a turn when the mayor learns about Wilson's new title, prompting him to request that Mainwaring relinquish his role in the ceremony.