Agatha Christie's Poirot - Season 3 - Eps 7: The Double Clue
Japp (who is really worried that failure could cost him his job) seeks Poirot's help in investigating a series of jewel thefts, and two remarkable things happen. Poirot falls in love (with the beautiful and clever Countess Vera Rossakoff) and he also meets a criminal intellect which he finds worthy of him. As the countess is his main suspect, Poirot spends most of his time with her - which for once leaves Hastings and Miss Lemon to do most of the actual detective work. In the end, this case may have to be put down as the one that got away.
About Agatha Christie's Poirot

Title: Agatha Christie's Poirot
First Air Date: 1989-01-08
Last Air Date: 2013-11-13
Status: Ended
Rating: 8.144/10 (from 492 votes)
Language: EN
Seasons: 14
Total Episodes: 70
Network: ITV1
Genres: Crime, Drama, Mystery
Production Companies: The Computer Film Company, Picture Partnership Productions, Carnival Films, LWT, GBH, A+E Studios, Agatha Christie Limited, Masterpiece, Granada Productions
Synopsis
From England to Egypt, accompanied by his elegant and trustworthy sidekicks, the intelligent yet eccentrically-refined Belgian detective Hercule Poirot pits his wits against a collection of first class deceptions.
Cast

David Suchet
Hercule Poirot