In Netflix's uneasy "The Good Nurse," Jessica Chastain suspects Eddie Redmayne of killing patients

The first scene of "The Good Nurse" has a hospital patient coding as they suffer a fatal seizure. The death is shot discreetly from the doorway of the room; only the patient's legs and feet are seen as nurses rush in to attend to the situation. As the camera slowly enters the room, it focuses on Charles "Charlie" Cullen (Eddie Redmayne) in profile, silently implicating him as he watches the horrific events unfold. 

Director Tobias Lindholm ("A Hijacking") takes a subdued approach to telling this story of Cullen, who is not the titular caregiver, but a serial killer who murdered dozens — possibly hundreds — of patients for years by poisoning their IVs. The deaths occurred almost without warning; the uncalculated nature of them makes the crimes particularly insidious. (Cullen's motive for his actions are briefly touched on, but largely ambiguous.)

Based on a true story — Charles Graeber wrote the book which Krysty Wilson-Cairns ("1917") turned into the film's screenplay — "The Good Nurse" recounts Charles' killing spree not from his perspective, but mostly from the point of view of the good nurse, Amy Loughren (Jessica Chastain), who helped a pair of detectives Dan Baldwin (Nnamdi Asomugha) and Tim Braun (Noah Emmerich) connect the dots and collar Charlie after she realized what he was doing. 

Lindholm takes what could easily have been a TV movie of the week thriller and elevates it to an involving drama by keeping the danger spiky. There are quietly sinister moments, such as an episode where Charles "steals" medicine for Amy. (She suffers from cardiomyopathy, and requires surgery, but Amy is without health insurance and has to keep her condition a secret to keep her job.) There is also some real fear when Amy realizes the threat that Charlie poses to her family — she is a single mother of two — which prompts her to try to get him to confess. 

Much of the film focuses on the investigation, which is generally interesting because the detectives are stymied by the hospital's risk administrator (Kim Dickens), who is evasive when she is not stonewalling the cops. (She also demands to be present as hospital staff members are interviewed.)  It is quite satisfying when Braun has an outburst and dresses her down. 

"The Good Nurse" suggests how someone like Cullen, who arrived at Parkfield with "experience and good references" can move from hospital to hospital without being detected because no one says anything — not unlike how abusive priests are transferred from parish to parish.

The investigation into Cullen certainly has its snags. One concern is that a body is needed to prove their case, which means having to wait for another mysterious death to occur. (It doesn't take long.) Cue the exhuming of a corpse to gather sufficient evidence. 

But it is the film's psychological moments that engage the emotions. Amy certainly struggles with her decision to bait Charlie because of the risks she is taking (for her job and her family.) But she is a "good nurse" and cannot allow the patients she cares for die. 

Eddie Redmayne in "The Good Nurse" (JoJo Whilden/Netflix)

Lindholm does not sensationalize these situations too much, but he fumbles a bit when he intensifies scenes, such as when Amy wears a police wire to a lunch with Charlie, or a showboating moment where he is being interrogated by the detectives. Likewise, the film falters when it relies on a clunky visual motif of an IV bag rolling on to the floor to mirror Amy passing out in a hallway after discovering Charlie's method of killing. 

Mostly, the film gets by on the strength of the performances by Chastain and Redmayne. She radiates warmth and cares for her patients as well as Charlie until she comes to realize what he has done. A pivotal scene has Amy reuniting with an old friend (a terrific Maria Dizzia) who used to work with Charlie and confirms Amy's growing suspicions. Redmayne's Charlie generally comes across as affable — he is great with her kids — which belies his dangerous nature. "The Good Nurse" does not give him enough solo scenes, which keeps his dark side enigmatic, but Redmayne reveals enough of his madness once his carefully constructed mask slips. 

To the film's credit, the dramatic scenes between Chastain and Redmayne have an uneasiness to them. As he helps her calm down when she is having a health issue, his friendliness is a little creepy. As she tries to coax him to confess, what clicks is that viewers understand what each character fears or is hiding, and the tension comes from who is going to blink first. 

"The Good Nurse" is a chilling film because it raises unanswerable questions about how someone like Charlie could do what he did, and why hospitals did nothing to stop him.

 "The Good Nurse" is currently in select theaters and streams on Netflix starting Oct. 26.