"A Great Deliverance" from 2001 turns out to be the first Inspector Lynley mystery, adapted from the series of books by Elizabeth George. I haven't read them, but from looking over the reviews here, fans of the novels seem quite happy.
Nathaniel Parker is Thomas Lynley, the eighth earl of Asherton, who is a police inspector, and when we first meet him here, he's best man at his old girlfriend's and best friend's wedding and attempting to keep a stiff upper lip. He's called into a community with a troubled police force to look into a murder investigation in which a man was decapitated, and the man's daughter was found at the scene catatonic. DS Barbara Havers (Sharon Small) is assigned as his partner, and it's an odd coupling. She's a working class woman who puts no emphasis on her appearance, and she's living a high-pressured life caring for her demented mother. Added to this, her blunt mouth has gotten her into trouble, and if she can't make a go with Parker, this may be it for her and the force. She's extremely resentful of the aristocratic Parker before even meeting him.
This unholy alliance travels to the murder site and, in the midst of trying to solve the murder, try to work out their relationship. The question is, which is more difficult? Good mystery, gorgeous scenery, and excellent acting make this series a winner. I actually saw a later one before this one. Parker and Small are excellent together, and Parker is movie-star handsome and easily believed as an earl. Small, as the scrappy, intense Havers, does a wonderful job.
Can't wait to see more of this series.