Geraldine McEwan reprises her role as Miss Marple.

Geraldine McEwan ( The Magdalene Sisters , Wallace & Gromit ) reprises her role as Agatha Christie's spinster sleuth Miss Marple in four new adaptations. Guest stars include Jane Seymour ( Dr. Quinn ), Francesca Annis ( Reckless ) and Dame Eileen Atkins ( Gosford Park ). " Agatha Christie's Miss Marple , Series III " airs Sundays, July 15- July 2 9 at 9/8 p.m. CT on KET1 and Thursdays, July 19- Aug. 2 at 9/8 p.m. CT on KET2.

First, t he formidable Lady Tressilian reluctantly hosts a house party on her Devon estate on "Towards Zero , " airing July 15. Miss Marple, an old school friend of Lady Tressilian, is intrigued when her eccentric old friend Treves tells a story about a child murderer who was never convicted. When Treves is found dead the next day -- and another murder follows -- Marple is determined to find the killer.

Then, on "Nemesis , " airing July 22, Miss Marple is faced with her greatest challenge yet when she discovers instructions from the recently deceased Mr. Rafiel to investigate a "possible crime." But there's a catch -- she has not been told what the crime is.

Later, When Miss Marple stays at London's fashionable Bertram's Hotel, she enjoys the traditional décor, the impeccable service -- and the unmistakable atmosphere of danger behind the highly-polished veneer. Ably assisted by the hotel maid Jane and Inspector Bird, Miss Marple realizes that the truth behind Bertram's Hotel is darker than even she could have imagined -- especially when two of the staff are murdered. "At Bertram's Hotel" airs July 29.

Mystery! " Agatha Christie ' s Miss Marple, Series III " is a co - production of London Weekend Television, WGBH / B oston and Agatha Christie Ltd.