Father Brown - Season 3 Episode 1

Lady Felicia's chauffeur Sid sees a man disposing of a body but the police claim that the dead man, Archie Waterson, drowned himself and warn Sid to say nothing. Archie was working as an art restorer for eccentric Lord Masters but when Father Brown and Lady Felicia visit it is apparent that the supposed restoration is a front for an MI5 operation, headed by Daniel Whittaker, whom Lady Felicia knew in the war. Whittaker tries to blackmail Felicia into finding out what Father Brown knows about the dead man since the priest has found a message from Archie which will lead to the identity of his killer and their motive.