The Torchwood team arrives at a suburban home and meets with Detective Swanson. She tells them this is the second murder scene and there's writing in blood at both scenes. Swanson takes them inside and shows them that the killer wrote "Torchwood" in blood above the victims.
As Jack has Swanson clear the room so they can use their "special equipment," Swanson blames Jack and his team, noting that Torchwood runs wild all over the city and now someone wants revenge. Tosh checks all three victims and can't find any link between them or any connection to Torchwood. Swanson gets the DNA results on the hair but it doesn't match any profile they have. However, Owen realizes that the killer has retcon in their blood.
Back at the Hub, the team explains to Gwen that retcon is the drug they give to induce amnesia. Owen wonders if the drug is inducing homicidal mania, or covered up someone who was a killer already. Tosh starts to narrow the list of 2,008 people they've given the drug to, to see who fits the profile. Gwen suggests they use the resurrection glove to bring the victims back to life for two minutes to find out who killed them. Owen notes that Suzie thought the same thing when she abused the use of the glove. Jack is reluctant, but when Gwen points out the murders are because of Torchwood, he removes it from the vault and uses it on the first victim, Alex Arwyn. It doesn't work for him, and Owen notes it didn't work well for anyone but Suzie. Gwen points out that she didn't use it and they let her try. It works for her and Jack tries to get answers. They don't get anything and Gwen begs for another chance, but Jack tells her that it only works once per body. They use it on the second victim, Mark Brisco, and he mentions the names Max and Pilgrim. Mark says that his wife was always talking to him, and then gives the name Suzie.
Later, Tosh matches the name "Pilgrim" to a support group run by Mark's wife Sarah. They realize they didn't know enough about Suzie to know if she'd attend such a group. They go to a storage locker where all of Suzie Costello's items are kept in storage, including a book of poems by Emily Dickinson. Tosh finds a Pilgrim membership certificate and Jack decides it's time to bring Suzie back. He goes to the morgue and brings out the body. Tosh can't stand to look her former comrade in the eye and leaves. Gwen uses the glove and relieves the last moments of Suzie's lives. She explains that Suzie is too far gone, but Owen notes she used a knife made out of the same metal. Gwen says that they'll have to kill Suzie again and Jack kills her using the knife. Suzie comes back to life and realizes that Gwen is using the glove. Jack demands to know what Max's last name is and Gwen refuses to let her go. She collapses and Ianto confirms that Suzie isn't dead, just unconscious.
Later, Jack and Gwen go to see the captive Suzie in an interrogation room. They tell her she's been dead three months and now she's stuck. She asks to see her father and they explain he wiped her records and they don't know who he is. Jack interrogates her, asking the last name of the Max she gave the retcon pill to. Suzie explains that she gave him a pill a week for two years, after she talked to him about Torchwood just to relieve her stress and have someone to talk to freely. She claims not to know Max's name and Jack pushes her for answers. Suzie goes over the photos and notices one member, Lucy McKenzie, isn't shown. She worked at a club and Suzie finally remembers the name.
At the club, Gwen, Owen, and Jack look for Lucy. At the Hub, Tosh monitors the situation while Suzie first taunts Gwen about using the glove, and then Tosh about the fact she can't look Suzie in the eye. Owen spots a man who fits the profile as he moves toward Lucy. Watching via remote, Suzie confirms it isn't Max. Another man attacks Gwen and Suzie warns her, and Jack stuns the man.
Back at the base, Jack and Owen interrogate Max but all they discover is that he goes into a homicide rage when he hears the word "Torchwood." Owen wonders what they're going to do about Suzie but leaves it up to Jack to decide. Meanwhile, Suzie asks Gwen to let her see her father and explains he has cancer. The two women start to bond and Suzie admits that it's upsetting that Gwen is doing better at her job and the others prefer her. Gwen insists she's not a replacement, but Suzie notes that Gwen is sleeping with Owen, just like she did.
Angry, Gwen goes to confront Jack, saying that he ignored the fact Suzie would become obsessed with the glove because her father was dying. Jack figure that Suzie is still alive because Gwen blames herself and wants her to remain alive. He admits that they're both responsible and wonders what they're going to do next. Jack insists that he'd rather kill her and let her live forever the way he does.
Owen goes over the footage of Gwen bringing back the murder victims. The monitors reveal that Suzie is draining the life force from Gwen to maintain herself. Jack realizes that the glove resurrects at the cost of another life and they have to kill Suzie.
While he shows his findings to Jack, Tosh, and Ianto, Gwen takes some biscuits and coffee to Suzie and slips her a note asking if she wants to leave.
Jack goes to the interrogation room and realizes Suzie and Gwen are both missing. Tosh tries to scan for them and spots them getting into Gwen's car. As Jack and the others go to get her, the Hub goes into emergency lockdown. Ianto can't reverse it.
Gwen explains to Suzie that she's taking her to see her father and that's it. Gwen figures that Jack will catch them but Suzie says they might get lucky.
Tosh and the others try to figure out a way to override the lockdown. Jack realizes that Max is responsible. They go to his cell and realize he's reciting a poem by Emily Dickinson, a verbal code that Suzie planted when she was alive. She planned the entire thing from the start. In anticipation of her death, she programmed Max to start killing three months after she failed to make contact with him. She Suzie figured Torchwood would capture Max and bring her back to life to solve the murders. Then Max would recite the verbal code, allowing her to escape.
As they drive, Suzie asks if she remembers correctly that she shot Jack through the head the night she died. Gwen confirms that she did kill Jack but he can't die, and Suzie wonders how Jack can be judgmental.
Ianto manages to open up a cell phone transmission and Jack calls Swanson to ask for help. He asks her for a book of poetry.
As Gwen drives, they listen to a song on the radio and Suzie remembers her mother singing it to her as a kid. Suzie starts to cry at the memories.
Swanson calls all of her staff around to listen as he explains that they're locked in their own base. Swanson then gets a book of poems by Emily Dickinson and has her read through it to get the verse they need.
As Gwen grows increasingly more fatigued, Suzie wonders about what she believes happens after you die. Gwen admits she isn't sure and Suzie explains that there's nothing… but there is something in the void, and it's coming.
Jack continues to have Swanson read poems as he repeats them out loud. None of them work but Tosh realizes that numbers might undo the word code. They read the ISBN and the lockdown ends. Tosh tracks Gwen's car to Greenleaves Hospital and Owen warns that Gwen only has approximately 40 minutes to live. Jack calls Swanson to have her give him priority on the roads.
Gwen takes Suzie to see her father, who is in ICU. Gwen realizes that her head is bleeding from the same wound that Suzie inflicted on herself, while Suzie is healing. Suzie wakes up her father and then kills him, explaining it's what he deserves. Suzie then wheels Gwen out of the hospital and calls Jack. Jack warns that they're going to catch up. He insists that if Gwen dies, he'll kill Suzie. When he asks why Suzie is willing to sacrifice Gwen's life, Suzie says that she'd do anything to live, knowing what is waiting for her on the other side. Suzie admits she was never any good and apologizes, and then hangs up.
Tosh realizes that Suzie is heading for a ferry at Hedley Point, and Owen confirms they only have minutes left. Suzie arrives and carries Gwen toward the ferry, insisting they can keep on going. Jack and Owen arrive as Suzie is forced to abandon the dying Gwen. Jack corners her on the pier and tells Suzie to let her go. Suzie says that he can't kill her because she has the last bit of Gwen. Jack shoots her down but Suzie continues to live as she refuses to die on him. He continues to shoot her and finally realizes that the glove is keeping them connected. Jack tells Tosh to destroy it. Suzie looks up and tells Jack that there's something in the darkness... and it's coming for him. Tosh destroys the glove and Suzie dies once and for all as Gwen revives.
Later, Jack returns Suzie's body to the morgue. He tells Ianto to put "Death by Torchwood" on the certificate and figures it's all over. Ianto warns that gloves come in pairs.