A police officer drives out to an estate and the officers run inside. In the nearby woods, an unconscious Tom falls out of a tree, covered in blood.
Twelve hours earlier
At the beach, Tom wakes up to an alarm clock. He’s in a trashed hotel room, and a lockbox is on the table with the words “fuck you” written on it in his own blood. Tom opens it and removes his wedding ring and a key, and then uses the key to unlock the chains fastening him to the radiator. He plays back the Dictaphone and Hyde warns him that since he didn’t sleep, neither did Tom. Hyde suggests that Tom let him drive, but Tom records a message warning him not to trash another hotel room. Tom finds the words “When you sleep... I will eat your children” written on the wall in blood.
At the institute, Benjamin complains to Peter and the security guard, Pete, that someone erased all the security tapes that might have shown how Mrs. Jackman escaped. He turns to Pete and demands an answer, but Pete insists that he doesn’t know. When he starts slamming Pete into walls, Peter tells him to stop. He tells Pete that Benjamin is finished and sends him to the nurse and then find someone to fire him. Once the security guard leaves, Benjamin tells Peter that “she” is coming because they screwed up at the zoo, and tells Peter to pray that they find Tom before she gets there.
Tom goes to the railway station and notices that the lights are flickering. He clenches his fists hard enough to draw blood as he remembers the message in the hotel room, and changes briefly into Hyde. In his head Tom hears Claire whispering to him to sleep until he dozes off.
Miranda and Min meet with Katherine at Tom's flat and show her a photo of Sophia Jackman, Tom’s mother. When Katherine says that the photo is an exact match, Miranda points out that it’s 15 years old. More importantly, all the records show that she died 15 years ago. Miranda points out that it’s very difficult to fake a death, and wonders if Mrs. Jackman might be a ghost. When Katherine dismisses ghosts as an impossibility, Miranda points out that given Tom’s dual nature, there’s no such thing as an impossibility.
A mother and child miss the train and go into the waiting room where Tom is sleeping. She goes out to get tickets and tells her son to stay put, but he goes over to Tom. The lights flicker as Hyde spins around and snarls at him. When the boy screams, his mother runs in and Tom, back to himself, assures her that her son is fine. The boy says there was another man there but his mother insists that there wasn’t anyone else there. Tom promises that he won’t let Hyde hurt anyone else and goes out to the platform. As the train approaches, Tom steps to the edge of the platform.
Tom calls Katherine from the train, unaware that Freeman and his technicians are monitoring the call. When Tom avoids saying anything specific, they realize that Benjamin and his people are listening in. Miranda tells Katherine to have Tom hang up, but first Katherine warns Tom that he needs to let Hyde out occasionally or he’ll be worse when he does get free. Tom warns that Hyde has threatened to kill his children, and then hangs up when Miranda takes the phone. However, they realize that Tom didn’t withhold his number. However, Freeman is able to trace the cell phone even though Tom has turned it off.
Next, Tom calls Claire on her cell phone, and she says that she’s at a friend’s house. She asks if he’s all right but Tom ignores the question and asks where the boys are. Claire wonders if he thinks she’s staying with a man friend, and asks if it would make a difference. The lights flicker and Hyde starts to emerge, and Tom tells her not to tell him where she or the boys are. He hangs up and the lights continue to flicker, and Tom hears and sees Hyde, posing as Claire, telling him to sleep. Tom realizes that it’s Hyde, and Hyde tells him to let go. When Hyde tries to flirt with him, Tom tells him never to speak through Claire’s mouth. Hyde persists, asking why Claire is so important, and Tom finally tells him to look inside his head if he wants to know. Hyde/Claire staggers back and Tom tells him that he’s not ready to understand.
Freeman gets a fix on the train and Benjamin orders his team to get ready. They’re waiting for Malcolm to finish constructing a metal man-sized containment unit.
On the train, the passengers look nervously at the lights and one of them seems to realize that they’re centered on Tom.
Peter prepares to leave for the night and can’t resist a few jibes at Benjamin’s expense. Benjamin knows that he’s seeing a receptionist at the institute and wishes him a safe trip home.
The next morning, Malcolm escorts the assault team as they take the container out. Meanwhile, Benjamin addresses his people, telling them that they are at the culmination of a hundred years of work. He tells them that Dr. Jackman is coming home and that no one can screw up.
On the train, Tom returns the cell phone to Dave, the passenger that he borrowed it from.
Benjamin confirms where Tom is and tells his men to move in.
As Tom gets off the train, Dave tells him that whoever she is, she’s not worth it. He advises Tom to dump her, and says that he’ll feel like a different man.
Tom wakes up briefly as more police arrive at the estate and mutters Claire’s name.
Eight hours earlier
Peter arrives home at the estate and calls to the woman that he’s expecting that he's home. He gets no response and goes into the study to check his messages. Tom has left a message saying that he’s coming to see him with questions. Peter closes the windows and discovers that one of them is broken. He calls for Tom, who steps in behind him. Peter calmly offers him a drink and pours himself one, and says that his daughters are out of the country. Tom knows about Peter’s affair with the receptionist, and explains that he’s taken precautions to prevent people from finding him.
The institute team closes in on Dave as he talks to someone on his phone.
Peter asks Tom what’s he learned, and Tom tells him what he’s learned about the real Dr. Jekyll, who experimented on himself and created a demon. Peter says that Hyde is a superman, pointing out that human beings no longer evolve. However, Jekyll changed that and passed it on to Tom, his descendent. When Tom points out that Jekyll had no children, Peter agrees. Tom convulses briefly and the lights flicker, and he tells Tom that it happens when he’s holding Hyde in. Peter looks for some paper to take notes and explains that Klein & Utterson exist for the sole purpose of tracking Tom. He then injects Tom with a sedative, and Tom warns him that when he goes to sleep Hyde comes out. Tom tells him to sit and looks for rope, and then pulls a knife and forces him to sit down. As he tapes Peter to the chair, he says that Hyde will kill his children since Tom has locked him up for a couple of weeks.
As Tom wheels Peter to the wine cellar, Dave knocks at the door and says that he followed Tom there. Peter manages to scream for help and Tom shoves Peter down the cellars into the wine cellar. Helicopters fly overhead as Tom runs to the door and tells Dave to run for his life. As Dave runs away, Tom tries to hold Hyde in. He runs down to the wine cellar and locks the door, and then prepares to put the chains on himself. However, he realizes that Hyde has the combination to the key box so he forces Peter to swallow the key to the chains. However, Tom realizes that Peter was on the floor and someone stood him up. Claire steps out and Peter explains that she was worried. The lights flicker and Tom tells her to look away. His wedding ring falls off as he transforms into Hyde.
A police officer finds Tom in the woods and wakes him up. When he points out that Tom is covered in blood, Tom confirms that it isn’t his and admits that he doesn’t know what happened.
Hyde tells Claire that Tom is gone and warns her that he hasn’t had sex in weeks. Claire turns to Peter for answers, and he tells her that this is where Tom goes. Claire recognizes Hyde as “Uncle Billy” and asks where Tom is, and Peter tells her that Tom and Hyde are one and the same. Claire asks how it happened and tries to slap Hyde when he tries to kiss her. He bites her hand and she grabs a bottle to defend herself, and then runs upstairs only to discover that the door is locked. Hyde tries to work out where the key is and realizes that Peter knows. He notices that Peter has been dribbling around the mouth and figures out where the key is.
Tom finds the key in his hand and tells the officer to arrest him. When the officer wonders why, Tom tells him that he’s the killer.
Freeman tells Benjamin that they’ve picked up Tom on the security cameras inside Peter’s home. Benjamin tells his men to stand down until he arrives.
Hyde finds a set of kitchen knives and prepares to cut Peter open. Peter insists that he’s on Hyde’s side and reminds him that Tom has never let him kill. Unimpressed, Hyde knocks him out, and Claire tries to knock Hyde out. He barely notices and she hits him harder, knocking him out.
The officer takes Tom to his car, and Tom realizes that the key he was holding is smaller than the one he forced Peter to swallow. He sees Peter come out with the police inspector and realizes that someone else is dead.
Hyde wakes up and finds Claire sitting across from him, holding the key to the chain locks. He lunges at her but comes up just short. Claire tells him that she has questions. Hyde insists that he’s not Tom and she’s not married to her, and Claire slaps him repeatedly, demanding to know how many people he’s had sex with. He boasts that he doesn’t keep count, and explains that Tom doesn’t have sex with her because he’s afraid that it would release Hyde. When Claire wonders if that would happens, Hyde asks if the idea intrigues her and she wonders if he’s flirting with her. Claire wonders why the real Tom didn’t tell her what was happening, and Hyde insists that he is real. She persists, asking if Hyde used protection, and he admits that Tom makes him. When Claire gets too close, Hyde warns that she almost came to close. She points out that he spent a night with her children and she has nothing to worry about, but Hyde warns her that he doesn’t know when to stop. Claire asks why he warned her then.
Claire notices that Hyde’s clothing doesn’t fit and tells him to turn around. He does so and she realizes that Hyde is taller, slimmer, and younger than Tom. Claire wonders if he has Tom’s memories, and Hyde admits that he only has bits and pieces. He insists that he knows what she looks like naked, but Claire doesn’t believe him. When he realizes that he won’t get anywhere with her, Hyde points out that she’s in Peter’s house and suggests that she was having an affair with him. Claire accuses him of being jealous and the lights flicker. She wonders how the two of them live and Hyde says that Tom has been chaining him up since he found out about Claire and the kids. The lights flicker again and Claire realizes that it has something to do with Tom. He admits that it means that Tom is trying to come through when he hears Claire’s voice, and Claire demands to talk to him. The lights flicker again and Tom returns. He tells Claire that Peter is one of them and she can’t trust him, but then Hyde takes control and grabs her. She knees him in the groin but he manages to grab the knife and tells her to give him the key. She swallows it, sure that Hyde won’t hurt her because he is Tom Jackman. Hyde leans forward and kisses her.
At the station, Tom insists that he killed his wife but has no memory of it. When the police inspector wonders what he means, Tom warns him that he has violent episodes and should be put in restraints. The inspector doesn’t deem it necessary despite Tom’s warning. The inspector is called away to talk to the institute‘s men and Tom asks the officer if he can see Claire’s corpse. Before she can respond, the inspector returns and tells Tom that he’s being transferred.
After a moment, Hyde stops kissing Claire and then produces the key from his mouth. He was sure that she wouldn’t have swallowed it, and assures her that he had a backup plan in case she had. Claire asks Tom what they’re going to do, insisting that he’s sick, and Peter speaks up, saying there’s been a cure for over 50 years. Benjamin and his men break in, guns at the ready, and Benjamin tells Claire to step away from Hyde. He nods at her to do so and she moves back, and Benjamin tells the men to lower their weapons. Hyde asks who they’re going to take him anywhere when he knows that they won’t shoot him, and Benjamin points out that he’s become attached to Tom’s family. He makes a call and gives the word to go, and assures Hyde that he’s threatening Tom’s family explicitly and directly. Hyde smiles at that and then cuts Benjamin’s throat. He then picks up the cell phone and tells the people at the other end that Benjamin can’t come to the phone. The institute commander, Colonel Hart, aims his weapon and tells Hyde to stay where he is. Hyde reminds him that he has orders not to kill, and promises that he’ll kill at least four men before they can stop him. Hart lowers his gun and says that he isn’t supposed to kill him.
Hyde smiles and goes to Claire, and tells her that he liked killing for the first time. He asks if he can call her, blows her a kiss, and then goes up the stairs. He promises to kill all of them if they hurt Claire and then leaves. When Hart tells Peter that they’ll pull him in, Peter says that it isn’t necessary because Tom will turn himself in. He tells the men to tidy up and call the police.
Outside, Hyde climbs up into a tree and bays at the moon.
The next morning, a police officer drives out to an estate and the officers run inside. In the nearby woods, an unconscious Tom falls out of a tree, covered in blood.
Hart and his men take Tom out into a van. Claire is inside, tied and gagged. Peter tells the men to put Tom into the metal containment unit and they seal him in.