'See How They Run': The 'brutal' case that helped inspire the Saoirse Ronan murder mystery
Spoiler alert! The following post contains important details about the ending of the murder-mystery comedy "See How They Run" (in theaters now). Stop reading now if you haven't seen it and don't want to know.
We knew we smelled a rat.
In "See How They Run," a madcap whodunit set in early 1950s London, Saoirse Ronan and Sam Rockwell play mismatched detectives investigating the backstage murder of a film director (Adrien Brody) after a performance of the Agatha Christie play "The Mousetrap."
Actors, stagehands, and even the cops themselves are called into question – but the real culprit was prowling the theater aisles all along.
During the last 15 minutes of "Run," we learn that usher Dennis Corrigan (Charlie Cooper) was the one who killed the director – and he now plans to kill Christie (Shirley Henderson), too. Holding the "Mousetrap" cast at gunpoint, Dennis explains that he was the boy at the center of a high-profile child abuse case that went on to inspire the play. He felt that Christie exploited his childhood trauma, so when he learned "Mousetrap" was being adapted into a feature film, he decided to enact bloody revenge in hopes that the movie version wouldn’t be made.
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“The challenge when making a film in this genre is, how do you do something new when every plot twist that is possible has likely been done before?” director Tom George says. The answer: Look to Christie herself.
Although no real-life murders happened behind the scenes of "Mousetrap," elements of "Run" are grounded in truth.
“Mousetrap” follows a group of people trapped in a country manor during a snowstorm who all become suspects when a woman is found dead. At the end of the play, the murderer is revealed to be the older sibling of a boy who was killed in an abusive foster home. The murderer’s first victim was their foster mother, while the second is a magistrate who sent the children to that home.
“Mousetrap" was loosely based on the case of Dennis O'Neill, a 12-year-old boy who was violently beaten to death by his foster father, Reginald Gough, in 1945. His gruesome death made headlines, and Gough was sentenced to six years in prison after being convicted of manslaughter. Dennis' brother, Terence O'Neill, later published a memoir about their experience with foster abuse and neglect, "Someone to Love Us."
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"The real-life case was as brutal as can be," says screenwriter Mark Chappell. The O'Neill children were "put into foster care, and the foster parents mistreated them to a horrifying degree. It was very shocking at the time, as it still would be today."
At the end of "Run," the usher attempts to kill Christie before his plan is foiled by Ronan and Rockwell's characters. In actuality, the surviving O'Neills had no known friction with Christie over being the basis for "Mousetrap."
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"I believe that members of the O'Neill family have seen the play, and as far as I am aware, they do not have any issues with it," says Christie historian Julius Green. "There is no reason for them to, as the subject is treated with great sensitivity and understanding by Christie."
Dennis' objection to a film version of "Mousetrap" also has real-world origins. Before "Mousetrap" opened in London in 1952, Christie, who died in 1976, wrote a clause in her contract that the play couldn’t be adapted into a movie until after the West End production closed.
“That was the anecdote that started everyone down the path of (this film),” says Chappell, who found a work-around of sorts by setting “a murder mystery against the backdrop of ‘The Mousetrap.’ (Christie) was very protective of her twist endings. And she also thought the play would only run for eight months."
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Seventy years later, "Mousetrap" is still playing in the West End, and has broken the record for the longest-running show of any kind in the world. It has since gone on to influence other big-screen whodunits, including "Clue," "Knives Out" and now "Run."
"Any genre-defining work is going to be parodied, and when it comes to stage thrillers, they don’t come any more genre-defining than 'The Mousetrap,'" Green says. "Parodies will come and go, but the original will outlast us all."
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This article originally appeared on USA TODAY: 'See How They Run' spoilers: The 'brutal' real-life case it's based on