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They do it with Mirrors is the third episode in the fourth series of Agatha Christie's Marple. It was broadcast on ITV by Granada Television on 1 July 2009. The screenplay was written by Paul Rutman and the episode was directed by Andy Wilson. It was an adaptation of the Agatha Christie novel of the same name.


Miss Marple is requested to help her old friend Carrie-Louise, the loving wife of benign philanthropist Lewis Serrocold. Carrie-Louise is slowly poisoned by an unknown hand,and her husband and her sister Ruth want absolutely to save her from this dark menace.

Comparison with the original story

  • Gina is the adopted daughter, not the grandaughter of Carrie Louise who is much younger in this adaptation. Mildred is also much younger as well and not middle-aged. There is no Alexis Restarick and no Pippa. In this adaptation, Gina and Mildred are sisters.
  • The show begins with a fire in the study at Stoney Gates. Ruth van Rydock was at the house and claimed she saw a manning stealing into the room just before. She is worried about Carrie Louise's safety and asks Miss Marple to go to Stoneygates.
  • There is a sideplot involving Carrie Louise and Gina going for a swim in the lake. Carrie Louise almost drowns. Lewis goes in to the rescue but fares little better. Finally they are saved by some of the delinquent boys from the institute including one "Anthony".
  • The murder scene is changed. The members of the house were actually staging an amateur theatrical performance. Edgar doesn't go into the study with Lewis. Instead, he forces Lewis out onto the terrace and continues talking to him. Gulbrandsen is not shot but stabbed with a U.S. Army knife.
  • Johnny Restarick, Steven's father and Carrie Louise's ex-husband arrives at Stoneygates just around the Lewis is being confronted by Edgar Lawson and in fact helps to disarm him. He was thus on scene around the time of Gulbrandsen's murder and a plausible suspect.
  • Wally is made the initial suspect in the murder, owing to his absence to fix the fuses and the murder weapon being his. Wally tries to escape the grounds in a bicycle but was knocked over by the car carrying Ruth van Rydock who was just arriving. The police arrest Wally after treating his wounds but Gina protests to the police that anybody could have left the drawing room to commit the murder. She shows them that the drawing room had a secret door and passage that links it to the hallway; Miss Marple explains in her denouement that the passage was merely a red herring, before explaining Lewis' crimes.
  • While Edgar Lawson's character and role in the murders remains unchanged, his death was changed slightly in two ways - firstly, he is exposed for his involvement in the murders by Miss Marple, rather than confronted by the police, and secondly, he does not use a rotted boat to escape, but swims over the lake on the property. Lewis' efforts to rescue him remain unchanged.
  • There is no tension between Juliet Bellever and Mildred in this adaptation. Bellever has a much smaller role--she is chatted up by Johnny Restarick in order to gain admittance to Stoneygates.
  • The tension is between Gina and Mildred who are sisters vying for Carrie Louise's affection. Gina's real mother is changed to Katherine Ellsworth, and her death was explained to have been from a hanging, after she was found guilty of committing arsenic poisoning on three counts. Mildred planted a newspaper cutting of this history in Gina's drawer which upsets Gina. It was also intended to draw attention to the possibility that Gina could have been responsible for the (supposed) poisoning of Carrie Louise.
  • While the confrontation scene between Lawson and Lewis still was basis for the first murder and retained certain elements from the original plot, it was modified considerably for the adaptation: Everyone, bar Mr Gulbrandsen, goes to the study to watch a dress rehearsal of a play. While there, Edgar Lawson barges in to confront Lewis.
  • Lawson's reason for confronting Lewis is changed; he accuses Lewis of spying on him, rather than being his real father.
  • A new character was introduced - Whitstable Ernest, a young man serving time for fraud and embezzlement. Ernest helped Lewis with his financial corruption in exchange for rewards such as oysters and alcohol. When Lewis knew that Mr Gulbrandsen was going to expose him, Ernest torched all the records of his actions, which Miss Marple suspected when she smelt petroleum in the secret passage. When Johnny began to question Ernest, Lewis realised the danger he could create and so gave him oysters laced with arsenic; this did not kill him, but merely kept him out of harm's way. This adaptation had two murders, not three.
  • The show ends with Carrie Louise selling Stoneygates and the institution being closed. She is reconciled and closer to Mildred. Gina writes to tell Miss Marple that she had settled in Wyoming with Wally and that they had prospered.


  • Anthony (not credited)

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