They Do it with Mirrors
Miss Marple senses danger when she visits a friend living in a Victorian mansion which doubles as a rehabilitiation centre for 'delinquents'. Her fears are confirmed when a youth fires a revolver at the administrator, Lewis Serrocold. Neither is injured. But a mysterious visitor, Mr Gilbrandsen, is less fortunate – shot dead simultaneously in another part of the building. Also features an illegitimate child. The novel's first proper film adaptation was the 1985 television film Murder with Mirrors with Sir John Mills as Lewis Serrocold, Bette Davis as Carrie Louise, Tim Roth as Edgar Lawson and Helen Hayes as Miss Marple.
A second adaptation was aired on 29 December 1991 in the BBC series Miss Marple starring Joan Hickson as Miss Marple, Jean Simmons as Carrie-Louise Serrocold, Joss Ackland as Lewis Serrocold and Faith Brook as Ruth van Rydock. The film was basically faithful to the novel, with the exception that Alexis survives the attack on his life. Also, Ruth van Rydock is present at the house when the first murder takes place and Lawson attempts to swim across the lake, and does not use a rotted boat.
A third adaptation was aired on 1 January 2010 for the fourth season of the ITV series Agatha Christie's Marple, starring Julia McKenzie as Miss Marple, Penelope Wilton as Carrie Louise, Brian Cox as Lewis Serrocold, and Joan Collins as Ruth Van Rydock. This adaptation had several changes and additions.