Hrafn Grímsson is a police officer with dreams of becoming a detective. It’s not that long since he graduated, but he has still grown tired of the mundane work of the street police officer. He and his partner, middle aged and grumpy Vigfús, enjoy a break in the routine when they are called to check out a skull that was left in an abandoned storage compartment. Hrafn finds odd books there, about mysticism and esoteric matters. The storage unit belonged to Guðmundur, nicknamed Mummi, a troubled young man who committed suicide recently. Hrafn takes one book for review – about hypnotism, marked with the name of Aron. Vigfús takes one as well, an old dictionary. That night, Hrafn forces himself to go out and watch a football game with his workmates. He can’t stand this kind of empty, casual socializing, but he knows that if he makes himself out to be a loner, he won’t ever make a detective. That night he sees an odd young man in the bathroom, looking like he was on drugs – like a zombie. With him were two men, all dressed in black. Hrafn thinks this odd – but not that extraordinary – and heads home early.

That night, a member of the Icelandic parliament is killed. He is stabbed to death, just outside of the parliament building. Hrafn is put on duty guarding the crime scene in the morning and realizes that the description of the murderer matches the man he saw the night before. He notifies Engilbert, a detective on the case, about it. Hrafn can’t go out hunting for the suspect however – he has to write a report about the skull they found. He starts googling Mummi, it’s owner, and finds old stories about him and a gang of rebellious anarchists, led by one Aron Beck. In the interview Aron spouts violent sermons about how society needs to be uprooted and the forces that govern us with tyranny destroyed. He also learns that Mummi was sexually abused as a child by a priest, Ingimar, during summer camp.

Hrafn manages to summon enough courage to ask out a girl he likes, a hairdresser named Bíbí. He takes her to a seedy bar he frequents, realizing that it’s not the classiest joint ever, and means to take her somewhere else. But as him and Bíbí chat for a bit, he sees that Engilbert is there as well, and spends the evening talking more to the detective about the murder case, rather than Bíbí. He learns that the suspect is a man named Gísli and that he was likely on drugs, ecstasy was found on him and chemical traces in his system. As Hrafn is talking to the detective, Bíbí eventually ditches him, leaving Hrafn distraught.

Something is bothering Hrafn. The murder suspect was completely out of it the night Hrafn saw him before the murder. The two men accompanying him were also out of place. He also finds out that the suspect is related to the priest who sexually abused Mummi, a coincidence he can’t seem to shake. Hrafn is sent to Iceland’s main prison to pick up the murder suspect. Hrafn decides to use the trip to visit Aron Beck, who is in jail, to return the book he found in Guðmundur’s storage and try to get some information. Aron is hostile to Hrafn, mocking him, almost playing with him. He doesn’t get anything solid from him, but he does notice that he keeps a plastic skull and a photo frame with a black mirror, a setup that is eeriely familiar to what he found in Mummi’s storage. Aron also mentions the dictionary that Vigfús took and claims it isn’t his – an strange detail to mention unprovoked. Hrafn is certain that Gísli was somehow hypnotized or manipulated while on butyric acid, and that Aron Beck and his associates are involved. Hrafn realizes that Vigfús was hiding something behind his back, and busts him as he’s selling ecstasy to a junkie, ecstasy that he found in Mummi’s hollow dictionary. Hrafn is furious about it, but also thrilled as these are the same types of ecstasy pills that were found on the suspect.

Hrafn gathers together what he’s learned so far and approaches Engilbert with the information. He’s pulled into a meeting with Axel, the chief detective. He tells them his theory, that Aron Beck’s gang of anarchists, which include Mummi and two other men he saw that night before the murder, drugged and hypnotized the suspect and made him commit the murder. He also has a theory that all this is part of a plan to attack the three main powers in society: the legislative, judicative and executive branch. His theory is that a judge will be targeted next, the one who put Aron Beck in prison. Axel decides to listen to his theory, although wild, and place a guard outside the judge’s home.

That night, a young woman named Sólrún goes out drinking with her friends. Two men dressed in black slip something into their drinks and drag Sólrún away as the drug takes hold. A while later, the police officers guarding the judge’s home don’t notice anything wrong when a very drunk girl gets out of a black car and heads into the house – hardly material for a brutal murderer. The judge lets her in as she knocks on his door, after which she brutally stabs him to death, screaming “die, pig!” as she guts him.

The next day Hrafn is again on guard duty at a crime scene, frustrated that his prediction was correct and not prevented. He says too much to a reporter that’s nosing around to vent out his frustration, letting it slip that they had figured out that the judge would be the next target, but still he was killed. As Hrafn’s prediction turned out to be spot-on, then he’s dragged into a meeting with Axel and Engilbert. They’re going to bring Aron Beck in for interrogation, and they need to find something solid. Hrafn is certain that Beck is running this, with help from his anarchist gang on the outside. They get the victims, Aron hypnotizes them through mobile phone and then the victim carries out the murder. Hrafn tries to find the other possession’s in Mummi’s storage, but they’ve been sent to a second-hand store. He manages to find a black mirror photoframe and an old picture in the second hand store, the  picture showing Mummi working in a meat processing plant, using the same kind of knives the murders have been carried out with. He starts ringing up butchers, and finds one of them is Aron Beck’s grandfather. He confirms that Aron stole everything, probably knives as well. Hrafn accidentally breaks the black mirror frame and in it finds a picture of Mummi as a child, in the summer camp where he was violated.

Hrafn heads out to the priest Ingimar and breaks into his home when nobody’s there, desperate for evidence or connections to the case. He finds pictures of each year of the summer camp, one of them has Aron Beck in it with Mummi, as well as others from the anarchist gang. This is where they all met, maybe they were all raped. Ingimar then comes home and Hrafn takes the picture, asking the outraged priest if he really wants him to come back with a warrant, searching his possessions and computer thoroughly. The condemned child molester keeps his mouth shut.

Aron’s interrogation doesn’t go too well. He turns every question on its head and quickly disarms Hrafn, despite his preparation. Hrafn has to retreat out of the interrogation room, where he finds the priest in the police station reception. It turns out the woman who carried out the murder, Sólrún, is his grand-daughter. He realizes that both suspects are related to the priest. Hrafn rushes back to the interrogation room, claiming that Aron is organizing these murders for revenge against the priest, to torture him, as well as causing turmoil in society. This small victory gets them somewhere, but the case is not nearly strong enough.

Hrafn feels pretty good about himself, but is crushed when the reporter he talked to uses that information to put Axel in a real tight spot on a live interview, even mentioning Hrafn’s name. The two men that Hrafn saw with Gísli turn themselves in, saying that they were at the sports bar the night before the first murder, but claim that they had nothing to do with it. Witnesses can’t point them out at the bar where Sólrún and her friends were drugged before the second murder, so this seems to be falling apart. Hrafn figures out that other members of the gang must be involved, and that their alibis are made up. He tries to reach Axel and Engilbert, but has no luck, as he’s certain that the third murder is coming up soon. He can only leave messages and hope they are received.

In the middle of all this, he has to go to a wedding with his lesbian friend. He’s off shift, after all, it’s the weekend and he isn’t detective – yet. He goes to the wedding with her, buying himself a last minute clothing –  a long, leather coat. Hrafn meets Bíbí at the wedding, who is there accompanying her friend as well. He summons the courage to talk to her and apologizes for his behavior, which she graciously accepts. They talk and feel a connection forming between them. He even opens up regarding his past, the family he lost in an avalanche, and the dark gift he has been given, being able to see shadows of death moments before someone passes away. That night, he stays at her place. His messages are eventually received by Axel, who sends out police to fetch the other gang members, who turn out to have false alibis. They don’t catch the other accomplices, but manage to prevent them from drugging another relative of the priest.

The next day, Hrafn gets a phone call. It’s from Orri, an ex-member of Aron Beck’s gang. He needs Hrafn to hide him, knowing he can trust him and only him. Orri heard that Hrafn prevented the ecstasy sale from going through and heard his name in the TV interview, knows that he is honest and that he figured out that the judge would be the next target beforehand. Orri meets Hrafn and says that Aron Beck is using hypnotism, mixed with the drugs, to astrally projecting himself into the victim, taking over the body and carrying out his bloody justice – he has mastered the black art of soul travel. The skull and black mirror are key to the ceremony succeeding. Hrafn still can’t reach Axel or Engilbert directly and Orri will not go to the police station. Hrafn has to hide him until he can grab a hold of Axel, so he decides to hide Orri at Bíbí’s place. The other two members of the gang, still on the loose, are sure to be hunting Orri down this very minute, as he knows too much and is wanted by the police.

Hrafn leaves Orri with Bíbí, who doesn’t like it, but is still willing to help him out. Orri goes out to buy cigarettes and is snatched up by the members of the gang. They force him to take the butyric acid and have him hypnotized by Aron Beck, through mobile phone. Bíbí calls Hrafn and tells him Orri is missing, so Hrafn decides to drive out to the prison where Aron Beck is kept and try to stop the soul travelling. When he arrives the prison guards refuse to help him, as he has no backup or any credentials. It’s late evening and no visitors are allowed. Just then, Hrafn gets a phone call. Aron has possessed Orri’s body and has Bíbí held at a knife point. “Be there in ten minutes, or I’ll cut her throat. That’s a promise,” Aron says to Hrafn. “I’ll be there – I’m closer than you think,” Hrafn replies. There’s no way he can make it back to Reykjavík in time. All that’s left to do is to break into the prison.

Hrafn steals a tractor and uses it to bulldoze the prison fence, setting off high alert alarms. He disarms a prison guard and holds another at gun point to get the keys to Aron’s cell. Meanwhile, Aron figures out that something is wrong and that Hrafn is at the prison. He tries to stab Bíbí, who dodges and fights for her life. Hrafn manages to get in to Aron’s ward and into his cell, where he sits entranced, deep in hypnotic state, controlling Orri’s body. Hrafn is tackled by guards before he can enter the cell, but he throws them off and uses his last bit of strength to kick Aron in the head. Orri goes limp, just before stabbing Bíbí, who then calls for the police.

Hrafn wakes up in the hospital. The charges against him were dropped, as Axel found out what happened and put the pieces af the puzzle together. Soul travel is a hard sell for a murder method in court, but there are several witnesses with the same version of the story. Aron’s crew immediately folded and cracked when they found out that he had been caught and is in a coma since Hrafn attacked him. Hrafn speaks with Orri, who is recovering after the ordeal, telling him not to be sorry, it wasn’t him doing this terrible violence. As he heads outside to where Bíbí is waiting for him, Axel meets up with him and offers him a position as detective. All seems to be well. But then Hrafn sees a dark shadow – an omen of death.

What happens to a spirit that can’t return to its body? Orri hears a voice. A familiar voice, in his head. Just as before, telling him to stare into the mirror, to take a journey with him. Orri tries not to listen, but he can’t resist. Aron’s hold is too strong on him.

Orri comes crashing down from a fifth floor window of the hospital, hitting the pavement with a sickening crack. Hrafn rushes to him, Axel at his side. Orri is still alive, but barely. Hrafn holds him in his arms, asking why he did this, what he was thinking?

“He’s gone. I’m free,” is all that Orri can say before his life fades away, cradled in Hrafn’s arms like a small child.