Ordeal by Innocence

S3 E2: Delighted to be invited to the wedding of Gwenda, her former housemaid, Miss Marple travels to the isolated island where Gwenda lives with her fiance, Leo Argyle, and his grown children. Though they are happy for their father, the Argyles are still reeling from the murder of their mother and the execution of their brother Jacko for the crime. Then a stranger arrives who exonerates Jacko, leading all to realize that the real murderer is still in their midst.