When Hercule Poirot's holiday at the idyllic French resort of Merlinville-sur-Mer is rudely interrupted by a letter pleading for urgent help, you can be sure it is the prelude to an evening of mystery and intrigue.
The great Belgian detective Poirot (played by Paul Evans) is shocked to discover the letter writer has been murdered before he can reach him, meaning there is plenty to keep his famous "little grey cells" busy untangling a fiendishly laid plot.
Evans carries off a convincing portrayal of Poirot, lending suitable gravitas to Agatha Christie's most celebrated fictional detective, while ably supported by Deborah Ussery as the detective's assistant, Abigail Fletcher.
As for the murder, there are plenty of clues around, but which are important and which are red herrings?
Why is Monsieur Renauld, the dead man, wearing an overcoat that is too long for him? What is the significance of the length of lead pipe lying on the ground? Why was a crucial wristwatch two hours fast?