Locked In (2023) Ending Explained – Who tried to kill Katherine and why?

Locked In Plot Summary

Locked In opens with brief snippets of a crime occurring, before cutting into a POV shot of our comatose patient, Katherine. Only, it turns out Katherine has Locked-In Syndrome, so she can still communicate through blinking. We soon learn that murder is on the cards, and Neuro Clinical nurse Nicky Mackenzie is on the case to figure out what’s really going on. Who tried to kill Katherine? And why?

What was Lina’s childhood like? Why doesn’t Katherine like her?

Growing up, Katherine was rich and famous, thanks in part to her husband’s wealth. However, he cut Katherine out of the will before he died and left everything for his son Jamie instead. Around this time, Katherine also adopted a daughter, Lina.

Jamie and Lina were close as kids, with both finding kinship in their loss of parents. Despite basically being siblings, they grew up and decided to get married.

Katherine is not happy, believing that Lina is a gold digger and giving a bitter speech at the pair’s wedding. Katherine is convinced that Lina is trying to steal the fortune and inherit it for herself. However, Jamie suffers badly from seizures and that deteriorates further as he gets addicted to pain medication, prescribed by Dr Lawrence himself.

It turns out, in a big coincidence, Nicky used to look after Jamie when he was a patient in the hospital. She also found our Dr Robert Lawrence was the one who gave him the painkillers, with a dosage way above normal levels.

Does Lina have an affair? What happens to Jamie?

Dr Lawrence and Lina end up having an affair during our flashback scenes. The latter drifts away from Katherine and Jamie as a result. That is, until Katherine drops the bombshell at dinner one night that Lina’s mother never cared for her and it was Katherine who pushed for adopting Lina to prevent her ending up in a foster home. Now Katherine is convinced that Lina is just using them to get their fortune, which is why the pair have been at logger-heads all this time. The argument soon ends with Lina telling Katherine that this is her house now.

As for Robert Lawrence, he became a doctor to please his father, but it left him feeling empty. This is a similar feeling to Lina’s emptiness over the lack of love from Katherine, hence why they end up together.

Lina eventually decides they need to end the affair, as she’s going mad sneaking around behind Jamie’s back. Lawrence though murders Jamie in the lake, dragging him to the depths and that’s the end of him. So naturally at that point, we know he’s the culprit.

What do Lina and Lawrence do about Katherine?

Lina decides to leave the mansion when she notices Lawrence getting hot and heavy with Katherine in the house some time later. When Lina tries to leave, Lawrence chases her through the house, but Katherine is on his side. Lina ends up stabbing Lawrence’s hand while hiding in the adjacent room. She grabs a gun and loads it with bullets, but Katherine pushes Lina down the stairs and takes the gun for herself.

Lian rushes off through the woods and a chase ensues. Katherine tries to shoot Lina from afar on top of her horse, while Lawrence drives to her location.

In the present, it turns out Lina and Lawrence are working together and Lina suggests they work and take Katherine home immediately before she can talk to the police. Then, they’ll “finish this”. The pair hurry to take Katherine from the hospital, but Nicky shows up and finds them gone. No one notices them leave on the cameras, as they race out the hospital without setting off any alarms and take her home.

What happened on the night of the murder?

Nicky spots the pair leave and locks eyes with Lina in the car. At the mansion, Lawrence crushes some pills and decides they’re going to stage having Katherine die in her sleep. However, Nicky messages Lina and reveals that Katherine tried to save her, which is why Lawrence turned and ran her down. Katherine didn’t try to shoot Lina after all.

Lina makes a decision and tells Lawrence to sort the car out. Alone, Lina listens to the message and we see properly what happened that night. Katherine changed her mind, shot the tyres on Lawrence’s car, prompting the good doctor to turn and change his target.

In the road, Lawrence approaches Katherine while she’s on the ground. Katherine urges him to “let her [Lina] go” She continues: “We still have the diary, there’s nothing she can do to hurt us.”

Katherine promises to tell the truth should he hurt Lina, so Lawrence runs her down and that’s how Katherine ended up with Locked-In Syndrome.

How does Locked In end?

After learning the truth, Lina flips her motivation and decides to work and stop Robert Lawrence instead. Lina stabs Lawrence with the syringe, emptying it into his neck. Lawrence, in his groggy state, still tries to inject Katherine. Just before he does, with the needle still sticking in Katherine’s arm, Lina stabs Lawrence in the chest, who collapses on the ground in a pool of his own blood.

Police and paramedics arrive at the scene and take Lawrence away. Katherine and Lina hold hands on the porchway, while Nicky just randomly watches on beside them like a lemon.

Will Lina go to prison?

The ending doesn’t make this explicitly clear but it’s fair to say that Lina is definitely going to jail. The evidence inside the mansion will show that Lina stabbed Lawrence in the chest (her fingerprints are all over that knife) while Katherine won’t be a reliable witness, given her state. We know that Lawrence and Lina kidnapped Katherine from the hospital and there will undoubtedly be witnesses to that, even if Nicky decides not to testify.

There’s also the evidence across the house of Lina stabbed Lawrence in the hand upstairs, and of course her fingerprints will be on the syringe she injected into his neck. So although Katherine and Lina do make up at the end, it’ll be short-lived given Lina is probably going to prison for murder for a long time, if not for life.


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7 thoughts on “Locked In (2023) Ending Explained – Who tried to kill Katherine and why?”

  1. How did Nicky know about Katherine’s intention when she called Lina? Katherine has locked in syndrome and uses her eyes only, how could she message Lina and say “She was trying to save you?”

  2. So the nurse kept concealing her fingerprints – with no explanation – annoying.
    Why was the nurse so bothered?
    Was expecting the nurse to be linas mum

  3. My interest is of a sequel or prequel concerning nurse Nicky especially as someone already mentioned she kept making sure she left no fingerprints and there’s nothing in the film as to why she could’ve or would’ve been doing it. At first I was wondering if she was Lina’s mom in some plot twist or previous married or involved with the doctor.
    Also not sure why Katherine was suddenly on Lina’s side

  4. I think there something about Jamie and nurse niky because in the end there is shadow behind nurse which is fliking

  5. Lina 100% in on killing Jamie, She told the Dr that she would do “Anything!” implying murder. I do think she was caught of guard however and was conflicted between her feelings. She wanted Jamie to die, but it was still a loss for her.
    My main question is, why is Nicki trying to conceal her fingerprints? She is very careful not to leave fingerprints when on the work phone and when opening doors. I believe she is definitely concealing something? She is also very involved in the families situation for an outsider, does she have history with the family or the Dr?
    Overall i found it very disappointing, there were so many chances for great plot twists, unfortunately it was very predictable.

  6. Lina should get a pardon. Firstly she sacrificed her entire childhood and adult life caring for jamie and being good to katherine who showed so much resentment without a reason. Its natural for a young woman who is deprived of any entertainment , love or any care from a marraige which is 100% giving and 0% receiving to be taken in an emotional path of atraction very cunningly planned by an evil man who uses both women to his gain. As for jamie’s drowning , she initially tries ti avoid the boat ride telling Jamie that its dangerous as he doesnt know how to swim and it was Jamie who pursuades her to go on the boat ride. And when the boat capsized she held on to jamie and tried hard to save him. She would have saved him if the evil doctor did not drag jamie down pulling him down untill lina coukd not drag him out further. She genuinely mourns Jamie’s death. Also when the evil doctor wants Lina to sell her house she says she wouldnt as its Katherine’s home and she wanted to keep her promise. All in all Lina is the real victim here. I hope the jury would with the help of the nurses testimony , release Lina from her traumatic life she had during her whole existence and let her live her life finally as a normal humanbeing .

  7. The reviewer got something wrong – Lina was not ignorant of the plot to kill Jamie. It was obvious through her tension, the doctor telling her to trust him, the looks she gave Jamie, and her lack of surprise at what the doctor was doing (Jamie kept questioning why he didn’t stop, whereas Lina was nervous but knew what was going on). She may have been scared but she was 100% complicit and guilty. We also see how despite some initial nerves, she enjoys continuing the affair with no remorse about Jamie’s death. I would certainly hope that she goes to prison for that!

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