Agatha Christie's Marple (2004)

S3E3 Towards Zero

At her lavish estate in Devon, a wealthy woman throws a gathering for her family and friends, among them her former schoolmate, Miss Marple. The celebration takes a dark turn when both the hostess and a solicitor are found dead. Determined to uncover the truth, Miss Marple sets out to track down the cunning murderer behind these sinister events.