Calypso Creek is a neo-noir psychological thriller film written and directed by Alfonso Cuaron and starring Asa Butterfield, Rupert Grint and Johnny Depp. The film surrounds a number of violent murders that take place around Calypso Creek, an amnesiac who is mysteriously connected with all of these murders, and two detectives who are trying to hunt down and expose the perpetrator of these murders.
Adrian Cage receives a bullet to the shoulder at the climax of a confrontation with Kenneth Kirk at Calypso Creek, and is hospitalised as a result of this. While in an ambulance, he has a fever dream about a young woman jumping into a river whispering his name and telling him that there is nowhere to hide any longer.
He is visited by his girlfriend, Theresa Finch, who informs him that she is pregnant with his child, but he is rendered silent by the experience so much that he cannot express his joy, which frustrates Theresa. Adrian is interviewed repeatedly about the confrontation between him and Kenneth, but he refuses to explain the true extent of events without his boss present, considering anybody else to have no right to the information he has to offer. His boss, Captain John Hancock, refuses to see him, leading to Adrian developing paranoia for undisclosed reasons. Meanwhile, a severely injured Kenneth is threatened by a figure wearing a mask, who tells him that he needs Adrian dead - it is implied that the majority of wounds sustained by Kenneth were inflicted by the masked man. Kenneth breaks into the hospital to kill him while he sleeps, but Adrian (in the middle of a nightmare) repeats the woman's words to him, and Adrian seemingly hesitates, before being shot in the back by Detective Edward Henley, who had come as representative to Hancock. Kenneth tries to escape, but Edward subdues him quickly before Adrian wakes up and pleads for Edward to kill the criminal. Edward responds by emptying the gun and tossing it to one side, making Adrian furious.
At the same time, a young man with the word 'Artemis' carved into his right arm and 'Apollo' into his left wakes up at Calypso Creek, only to be surrounded by the police when he discovers a smoking gun in his pocket. Unable to remember his own name or anything before waking up, the young man decides to call himself Artemis because he is right handed. He is interrogated by Hancock, and learns that the corpses of two teenage girls have been discovered in Calypso Creek, with evidence of sexual violence. However, it is revealed further that Artemis is innocent of the sexual assault at least because he has been castrated. Artemis only knows to ask after Adrian, who has never seen him before in his life and even seems to react violently at some points during the meeting that is arranged. Artemis explains that he remembers nightmares about the same girl as Adrian, and woke up from such a nightmare before he was arrested. He is held in police custody with it being debated as to whether or not his amnesia is genuine.
In his cell, Kenneth tells his interrogators that he took orders from a man who is somehow connected with Artemis, but refuses to disclose as to how until he meets him. Artemis has a conversation with Kenneth, who provokes him into having a seizure by reminding him about an event that happened at Calypso Creek. As they speak, a girl named Bethany Torrance is assaulted and nearly killed by a group of men at the Creek, but is warded of when a pack of dogs is set upon the men by an unseen person, who takes Bethany to a police station. Bethany recognises Artemis, who denies knowing her. Realising that Artemis is at the centre of the situation, Hancock charges him with the crimes with which he is associated. Artemis suddenly recognises Bethany, and has another seizure, after which he completely forgets everything that has happened. Adrian, fascinated by what is happening, decides to take on the case against Hancock's advice. He accepts the assistance of Edward, even though there is visible animosity between them. Hancock struggles to get through to Artemis without the risk of invoking any more seizures.
Theresa misses on a girl's night out as a result of her pregnancy, but later on her house is broken into and she is menaced by the masked man, who carves a vulture into Adrian's bedroom door, before leaving. When she tries to give chase, she trips and knocks herself unconscious. She is almost run over by a man named Felix, who instead carries her back into the house when he realises that she will be having a child soon. Felix leaves, only to be encountered and recognised by Adrian, who picks a fight with him. Felix diverts Adrian's attention with the news of the break-in, and escapes, only to be caught and threatened with castration by the masked man. For undisclosed reasons, the masked man records their entire conversation and leaves the recording with Felix, who goes to the police. Recognising that Artemis was castrated also, Hancock's suspicion of the young man heightens, before Adrian arrives and destroys Felix's credibility with the news that he is a criminal fence. Theresa blames Adrian for the stress she was under during the break-in, since she wouldn't have been at home if it weren't for her baby. Kenneth is put on trial in the meantime, and a prime witness against him is his own sister Martha, who cites his dealings with a young man named Artemis at Calypso Creek.
Artemis, having nightmares about the young woman again, is menaced by the other inmates at the station, but he reveals a vulture tattoo on his right shoulder, which mysteriously causes total silence throughout the entire station. It is believed that Artemis plans to escape, but Artemis suffers another seizure and forgets everything again. Edward studies his behaviour and suggests that the amnesia comes as a result of stress associated with whatever the vulture's meaning is. They believe that they have come across an underground gang of which Artemis was a member, but nobody who is interrogated suggests that there was a gang - only three individuals. Adrian and Edward investigate Calypso Creek and find evidence of constant violence throughout the place. Artemis, who has escaped, tells Adrian that the girl won't go away, before Adrian pursues him throughout the Creek and injures him in the fight that follows when Artemis believes that Adrian will kill him. While the two of them are fighting, Edward sees another body at the bottom of the creek - an aborted child, with Adrian's DNA.
Adrian recognises his own DNA, and Theresa's, and confronts her about it, but Theresa heatedly denies it being hers. Under suspicion of murdering the infant, Theresa herself is arrested by Adrian, only for Edward to defy him and detain them both on the grounds that Adrian has become mentally unstable and, in hindsight, shouldn't be a part of the case in the first place. Artemis escapes again, compelled by memories of the young woman in his dreams, and is confronted by the masked man. The conversation is not shown, but in the very next scene a beaten, bloodied Artemis is left at Adrian's doorstep unconscious and near death. Martha finds him and brings him to the hospital, where he is visited by a recuperating but near-crippled Kenneth. It is revealed that Kenneth is Artemis's biological father, and that Kenneth had a relationship with Theresa a long time ago which sired him. At the time Theresa met Adrian, she was secretly pregnant with Kenneth's second child and killed it moments from its birth because, by then, she had begun to realise the man that Kenneth was. Artemis asks to be brought to Adrian, and tells him this, knowing that Adrian will react violently towards either Artemis's absentee mother and father.
Adrian breaks out of the station and hunts after Kenneth, but Edward pursues him. Adrian drugs his nemesis and pulls him to Calypso Creek, where they found the infant's body, before preparing to execute him. Edward intervenes and Adrian accidentally shoots him in the stomach, while Kenneth makes his escape. The masked man anonymously warns Artemis to this, and Artemis confronts his father and violently beats him, before throwing him into Calypso Creek to die. Adrian pulls the man from the Creek only for the necessity of personally killing him, and Hancock appears and knocks him out. While Adrian is returned to his cell, and Edward and Kenneth are sent to hospital, Artemis confronts Theresa, who doesn't recognise him. Artemis, on the verge of another seizure, berates his mother for her abandonment of him and the murder of his brother, and when he has the seizure he too is arrested and sent to an asylum - his amnesia is not in doubt, but he is recognised to suffer also from borderline personality disorder, as is his mother. The masked man visits Artemis, Adrian, Edward, Kenneth and Theresa, and carves a vulture into the doors of their cells and wards.
Bethany visits Calypso Creek and is tormented by voices from her past, among them are Adrian, Artemis and Kenneth. Hancock follows her and demands to know what happened at Calypso Creek. Bethany explains that Artemis was raised as her adoptive brother, but their parents only adopted him for public sympathy - they referred to him only as 'the boy', and when he was six and asked for a name, they permanently drew 'Apollo' and 'Artemis' into either arm and told him to choose, as the only form of independence he would ever have from them. He has been suffering amnesia attacks his whole life, which has damaged his school record and even got him framed for crimes he didn't commit by almost all of the locals. With this record, Artemis descended into gang violence, until he prevented the masked man (whose face he has never once seen, but who had complete authority over him) from involving Bethany in vice. When the masked man himself tried to get Adrian to have his way with Bethany, Artemis defended his sister and got into a brawl with the masked man as a result. Adrian used this as an opportunity to try and gun down the masked man, only for Kenneth to attack him, leading to the showdown that ended at the start of the film. The masked man was wounded brutally by Artemis, but he had a seizure during the fight and was thus beaten and castrated in vengeance of his defiance. Unable to live with the strain that her existence had brought on her sister and 'brother', Sabine killed herself by jumping into Calypso Creek, which was inadvertently witnessed by both Adrian and Artemis. Martha listens in on this, and is killed by the masked man.
While Theresa is on trial for murdering Kenneth's second child, she goes into labour and gives birth to twins. In the meantime, the masked man infiltrates the prison and tries to kill her, but Theresa pulls a hidden gun on him, having bought it while in prison. She violently empties the gun into the masked man and presumably kills him, but he is revealed to be wearing body armour and staggers out of the hospital, which a maddened Theresa interprets as him being immortal. Hearing her cries, and attracted by the gunshots, Hancock faces off with the masked man, who eventually eludes him and poses as a pedestrian (but his face is hidden the entire time). Hancock chases him through London, into the London Aquarium, where the disguised masked man murders him by stabbing him with a needle. Hancock, delirious from the poison in the needle, sees the masked man spread wings and fly away. Bethany finds his body and calls for an ambulance, but despite an array of efforts by the hospital staff, Hancock dies ordering the release of Artemis and Adrian so that they and Edward can kill the masked man. Edward carries out his last request, even though the other officers try to stop him, and the masked man lures them to Calypso Creek.
Adrian is lured from the group by the masked man, where he finds his newborn daughter lying alone in a clearing. He takes her, but the masked man pulls a gun on him and forces him to make a decision: abandon his daughter forever and leave, or to watch his daughter die before he himself is killed. Adrian refuses to choose, before shooting the masked man with a concealed, silenced pistol he hides behind his daughter. The masked man, still wearing his armour, is only winded, but Adrian then shoots him in the leg. The masked man shoots Adrian in the head, killing him, but has completely exposed himself to the rest of the group since his gun wasn't silenced. A bloody manhunt breaks out between the group, and the masked man, who uses Adrian's gun as well as his own and takes the daughter as a hostage. He succeeds in wounding Edward, but wastes all of his bullets in the process. Kenneth takes him from behind and they struggle, before Kenneth is killed by a hidden blade. He uses Kenneth and Adrian's bodies as bait and lures Artemis into Calypso Creek, where Artemis fakes having had another seizure and not knowing who he is. The masked man lures him closer, only for Artemis to break his already wounded leg and turn the knife on him. The masked man exhausts himself in holding the knife against Artemis' neck, only for Bethany to appear and blast the man in black with two guns in the chest and head, deforming and killing him.
When Bethany, who was wearing gloves, drops the guns near Kenneth and Adrian's body, carries Artemis out of the woods, before Artemis hears the daughter's cry, and carries her back with them. Artemis suffers a seizure for real afterwards and dreams of Sabine jumping into the Creek, only for her to sprout swan wings and fly away. He wakes up in bed with Bethany and a paroled Theresa, remembering who he is and what has happened, but not knowing who the daughter is. Bethany, knowing that they are being recorded by a permanently disabled Edward, silently urges Artemis to remember Adrian and Kenneth killing the masked man, whose face has been destroyed and is therefore unidentifiable. They name the daughter Sabine, and attend the funerals of those who were killed by the masked man, but not before dismembering the man's body and casting him into Calypso Creek, never to be seen again.
While caring for Sabine, Artemis tells her he dreads telling her about what they have been through, and why she has no father, but tells her that he isn't afraid of forgetting about any of it, since they have all moved on. Knowing that Edward is listening in, Artemis asks to be left alone, and Edward (who is revealed to be across the street from him in a car) signals that he will, before Artemis watches him drive away.
- Asa Butterfield as Artemis, an amnesiac.
- Rupert Grint as Detective Adrian Cage, a harsh and vengeful detective who worked undercover for eight years in underground gangs.
- Johnny Depp as Detective Edward Henley, a calm and empathetic detective who was demoted for gunning down one of his partners in mysterious circumstances.
- Tom Wilkinson as Captain John Hancock, Adrian's boss.
- Ramona Marquez as Bethany Torrance, a girl who survives being murdered at Calypso Creek.
- Ray Winstone as Kenneth Kirk, a violent criminal and former nemesis of Adrian's who injured him in their last confrontation.
- Natalie Dormer as Theresa Finch, Adrian's unstable girlfriend.
- Imelda Staunton as Martha Kirk, Kenneth's estranged sister who served as a witness against him after his confrontation with Adrian.
- Christopher Eccleston as Felix, a notorious fence between criminals who occasionally deals with Adrian.
- Chloe Grace Moretz as Sabine Torrance, Bethany's older sister.
- Doug Jones as the masked man.