The Double Clue

The case is a string of stolen jewels, and Poirot is helping Japp chase the thief the way he has helped Japp chase a hundred thieves. Then Countess Vera Rossakoff arrives, and the case stops being routine. She is everything the countess in a Christie story should be: glamorous, Russian, possibly dangerous, and entirely too interesting for Poirot's peace of mind. The series is honest about what happens next. Poirot falls in love, and it shows. Kika Markham's entrance is the sort of scene the show does better than almost anyone, all certainty in a room full of quiet English caution.

The jewel theft still has to be solved, and the suspects present themselves in the usual parade: Marcus Hardman (David Lyon), Bernard Parker (David Bamber), Lady Runcorn (Charmian May), Mr Johnstone (Nicholas Selby), Redfern (Michael Packer). Hastings watches the whole performance with the expression of a man who has just realised his friend is human after all. Japp wants his thief. Poirot wants something he cannot quite name, and the countess, for her part, offers him a criminal intellect worth measuring himself against. The double clue of the title matters less than the double nature of the case, theft on the surface and something else underneath.

Anthony Horowitz wrote it with Agatha Christie, and Andrew Piddington directed. Kika Markham's Rossakoff is the engine of the episode, and she is worth the price of admission on her own.

The Double Clue is the episode where Poirot's guard slips, and it is a pleasure precisely because it is rare. He solves the case. But he loses a little something to the countess on the way, and the series is honest enough to let that stand. For a story about jewellery, it is really about the jeweller, and that is what makes it memorable.