Under Tosh’s directions, Owen and Grace are chasing a target on foot. Jack is closing in by car while Tosh tries to identify the target. She finally gets a visual on the target, a man wearing a hood. The target slides under a closing security gate and Gwen manages to follow him, leaving Jack and Owen behind until they can get the gate back up. Gwen manages to grab the target’s coat as they enter a station but he pulls himself free and gets away. Tosh congratulates her, telling Gwen that the jacket is the target. Gwen takes out a handheld alien device and pushes a button on it. She finds herself standing in the same spot. A young boy wearing older-style clothing comes out of an alley. He’s unable to see or hear Gwen, and has a tag on his coat with his name: Tom Erasmus Flanagan. He walks away and Gwen pushes the button again. She finds herself back to normal as Jack and Owen arrive, and Gwen tells them she’s seen a ghost.
Back at Torchwood, Tosh goes over the security footage but nothing there confirms what Gwen claims she saw. Gwen says that she could feel everything the boy was missing. Jack examines the device but doesn’t push the button. Tosh runs a check on the boy’s name but Owen simply looks the name up in the phone book and gets an address.
Gwen and Owen go to the boy’s address and talk to Tom: now a sixty-six year old man. He tells Gwen that he was evacuated to Cardiff during World War II as London was bombed. He was taken out into the countryside and describes exactly what happens. His description matches what Gwen saw at the station. He was left on his own due to a mix-up and wandered down a tunnel looking for someone until the authorities found him. Later, Tom was adopted.
Outside, Gwen and Owen are leaving as Gwen gets a call from Rhys. He wonders if she’s coming home and is disappointed that she can’t tell him when she’ll be there. Owen honks to get her attention and Rhys hangs up.
At Torchwood, Jack identifies the runner as Sean Harris, aka Bernie, a nineteen-year-old with a record of petty thievery. Gwen observes that the alien device lit up at the station, but it isn’t now. The team goes to Bernie’s estate but no one there has anything good to say about him or knows where he is. They meet under a bridge and Jack orders them back to the railway station so they can replicate the experience. As they go back to the car, the device lights up for Owen. He pushes the activation button and finds himself in the same spot, on a rainy night. He sees a woman talking about a “bastard.” The man comes after her, calling for “Lizzie.” Liz refers to him as Ed Morgan and says she was warned about him. Morgan advances on her, flattering her and getting close enough to kiss her. Morgan then grabs a knife and takes her to the side of the tunnel. Owen looks on helplessly, feeling everything that Liz is feeling. The effect ends and Owen describes everything that happened as he shakes in pain and horror.
Back at Torchwood, the team tries to put together how the two events are related. They realize the murder took place 40-45 years ago and that Liz is Liz Lewis, who was raped and murdered under the bridge in March 1963. Jack realizes the device is a quantum transducer, capable of converting strong human emotion and making it visible to the device user. Owen is desperate to find Morgan but Jack warns that they can’t reopen the case without new evidence and Owen can’t testify as a witness. Jack tells him to stick to the job and they’ll search for Bernie the next day. Owen takes all of the files and goes home.
Jack brings Gwen down to the target range and has her practice shooting. With some close contact from Jack, she does well on the first shot and soon gets the hang of it on her own. Once she’s done, Gwen wonders when he goes home and Jack tells her that the 21st century is when everything changes and he doesn’t have time to sleep. Gwen leaves for home and discovers that Rhys is out playing poker. Gwen takes the transducer out of her purse.
Owen is trying to sleep but is haunted by the emotions of Liz’s death.
Gwen activates the transducer and taps into a past emotion of herself and Rhys together on the day she became a police officer and told him the news. Then she brings up an emotion/memory of the two of them going to her mum’s party. Rhys then comes in and says he doesn’t mind her working late as long as she wants to come home to him. Gwen kisses him and the two embrace as Gwen hides the transducer in her purse.
Owen goes through the files on Liz’s murder and finds Ed Morgan’s name among the suspects interviewed. The next day he checks out all the Ed Morgan’s in the phone book and finds the man he saw, now 40 years older. Owen identifies himself as a gas inspector and gets himself invited in. Owen tells him to sit down and asks him if he remembers the Lewis family, and how they moved away after their only child died in 1963. He describes what Liz looked like when Morgan killed her and that he knows what happened that night. As Owen describes what Liz felt, Morgan snaps and tells him to get out, saying Owen will get nothing from him this time. Owen leaves, barely in control of himself.
As Owen goes to his car, he notices Bernie nearby and chases after him. Owen finally corners him and takes him to a bar. Jack, Gwen, and Tosh arrive and show him the device, and ask where he got it. Bernie explains that he and his mate got it from the locker of an old man who went soft in the head. He knows that the transducer comes on and makes the holder see things, and describes how he saw a woman throw her dead baby into the river. Bernie knew the woman, now elderly, and she paid him not to say anything. He also describes the same murder that Owen saw. As they leave with the transducer, Bernie asks if they want to see the other half. He takes them back to his flat and they put the two pieces together. They realize that it came through the rift. As they leave, Bernie warns that he only used the second half once, and that it allowed him to see his own death, out on the road and the same age he is now. Gwen tells him to wait and goes out to the street to tell Jack. The assembled transducer activates and Gwen sees… herself, holding a bloody knife. Future Gwen tells her that she couldn’t stop it and Owen came with a knife. Gwen snaps back to the present as Jack takes the device away from her.
Later, Gwen tells Jack what she saw. He explains that what she saw was only one possible future, but admits they don’t have any equipment that can verify that possibility.
At his home, Morgan considers making a phone call but stops.
Owen and Tosh have a drink and Owen tells her that he discovered where Morgan lives. Tosh has checked Morgan’s medical records and learned that he’s a paranoid depressive who has tried to kill himself and hasn’t left this house in years.
Morgan finally calls… Bernie.
Owen remembers Morgan saying that Owen wouldn’t get anything from him, and that he told him before.
At Torchwood, Jack remembers how Bernie described himself seeing Liz’s murder.
Gwen goes to see Bernie and tries to assure him that what he saw was only a possible future. Jack calls Gwen and tells her that Owen described his visit to Morgan. He figures that Bernie blackmailed Morgan and tells her to stay there while he and Owen go to Bernie’s flat.
Gwen confronts Bernie while Tosh checks the CCTV monitors and spots Morgan heading for Bernie’s flat. Bernie sees Morgan coming and goes outside while Gwen stays to answer a call from Jack. She realizes that what Bernie described was his coming death and runs outside.
Morgan, armed with a knife, confronts Bernie in the street. As Gwen runs up, Morgan talks of how he believed everyone knew he was guilty. When he sees Gwen, Morgan snaps at her while Bernie promises he won’t say anything. Jack and Owen arrive and disarm Morgan, but Owen grabs the knife and approaches Morgan. Gwen remembers what she saw as Owen holds the knife to Morgan’s face… and then gives the weapon to Gwen. Gwen, relieved, is glad that no one died. Morgan pulls himself free of Jack’s grip and stumbles, impaling himself on the blade as Gwen holds it. Owen tries to stabilize him without success while Gwen stares at her bloody hands in horror.
Later at Torchwood, Tosh points out that Morgan wanted to die, while Owen is relieved that, while he crewed up, he didn’t kill Morgan. Jack figures that the transducer isn’t meant for them and gives it to Ianto to place in the archives. Later by the river, Jack tries to assure Gwen that Morgan killed himself and she wasn’t responsible. He admits that they’re surrounded by emotional ghosts, and they have to learn to live with them all.