Based on Charles Graeber’s 2013 book “The Good Nurse: A True Story of Medicine, Madness, and Murder” with input from the real-life Loughren, the thriller is directed by Danish filmmaker Lindholm. “I had that feeling when I read the script of, ‘Can I play this person without the why?’ But then I kind of thought on that and ultimately realized that the why and knowing the why is our need as human beings to feel safe,” Redmayne told IndieWire in an interview earlier this fall. “As in, if we answered why Charlie Cullen did this, then we would be able to other him and go, ‘Oh, he did it for this reason, and that’s monstrous and we would never do that, so we’re safe.’ Whereas actually, that’s not how the world works and that’s not what he did.”

He added, “How this guy was ever allowed near vulnerable people is one of the shocking questions. But it also meant that as an actor, I had all of that research there.”

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