Telemystery: The First of Three Poirot Episodes and the Finale of The Killing, Sunday June 19th, 2011

You'll have to program your DVR as two mystery series overlap tomorrow, Sunday June 18th, 2011.

First, on PBS at 9 PM (ET/PT) -- but check your local listings -- is the first of three installments this summer of Hercule Poirot on Masterpiece Mystery!

In "Three Act Tragedy", an elderly Cornish vicar suddenly drops dead at a party, and everyone looks to fellow guest Hercule Poirot (David Suchet) to solve the murder. But the Belgian super-sleuth sees no foul play, correctly predicting that analysis of the clergyman's glass will yield nothing more than the remains of an excellent dry martini.

Before long, however, Poirot is summoned back to England from his boredom among the palms and irksome children of Monte Carlo. Another death among the same revelers has occurred, this time, indisputably, murder.

With the help of two enthusiastic amateurs — his old friend, the retired stage actor Sir Charles Cartwright (Martin Shaw), and Charles's jaunty love interest, Miss "Egg" Lytton Gore (Kimberley Nixon), Poirot questions the dramatis personae, as Sir Charles calls the party guests. And as Sir Charles embraces his role, donning a pair of patent-leather spats, Poirot works to unravel a perplexing mystery, building a house of cards, tracking a missing butler, and even hosting his own sherry party.

"Three Act Tragedy" is based on a novel of the same title by Agatha Christie (though originally published as Murder in Three Acts in the US). The book was previously adapted in 1986 with Peter Ustinov in the role of Hercule Poirot.

"Three Act Tragedy" runs for 90 minutes, which means it will overlap with the first season finale of The Killing on AMC (10 PM ET/PT).

This fine murder mystery series comes to a close in an episode titled "Orpheus Descending". If you have been watching The Killing, you won't want to miss the finale. If you haven't, you've got some catching up to do! Previous episodes are available on the AMCTV website. Watch a preview for the series' conclusion below.