Gwen Cooper

Gwen Cooper was a Cardiff Police Constable when she stumbled across a secret Torchwood 3 operation which involved the death of several people. She joined Torchwood at the invitation of Captain Jack Harkness, who valued her empathic nature and ability to see beyond the facts.

As a Torchwood operative she provided an essential foil to Captain Jack, although her personal agendas often interfered with her duties. Her actions and descisions are often guided by her desire to protect her live-in boyfriend, Rhys. She had a brief, disruptive affair with another operative, Owen Harper.

History
Gwen Cooper is introduced in "Everything Changes" as a police constable in Cardiff. She serves to introduce the audience to the concepts of the show as her character discovers them. In the first scene of the show, Gwen is called in on a murder scene, only to encounter a mysterious team of individuals known only as "Torchwood". To satisfy her own curiosity (especially after witnessing the killing of a hospital porter by a Weevil), she tracks down the team and discovers the truth behind the organisation.

Despite having her memory wiped by the team leader, Jack Harkness, Gwen manages to leave a reminder to herself, linking a trace memory to the reconstructed murder weapon, and ends up exposing the murderer, Suzie Costello, Jack's second-in-command. When Suzie commits suicide, Jack offers Gwen a position with Torchwood and she accepts. Gwen believes that the team has been working with aliens and alien technology for so long that they have become hardened and have lost touch with humanity. She acts as the moral centre of the team, reminding them that they are in a position to help people, not just to scavenge technology.

Unlike her colleagues who have let their professional lives consume them, Gwen maintains a life outside the Institute. She lives with her boyfriend, Rhys Williams, who is a transport manager. He believes any alleged alien interference with Earth over the past two years are actually mass hallucinations caused by terrorists putting psychotropic drugs in the water supply, a theory that when put to Jack by Gwen makes him deride her boyfriend as stupid. Before she dated Rhys, she was going out with a Bruce, and Owen speculates she simply settled for Rhys.

In "Ghost Machine" she is taught to use guns by Jack, and there appeared to be some sexual tension, but any developing feelings were apparently negated when she returned home and the "ghost machine" showed her memories of her relationship with Rhys. However, in "Cyberwoman" she and Owen kissed passionately whilst hiding from a female Cyberman, followed by further sexual tension with him in the episode "Countrycide", and the eventual revelation that she has embarked upon an affair with Owen, largely because she cannot share her supernatural and extraterrestrial experiences with her boyfriend, Rhys, even though she does care for him.

On the Torchwood website, Gwen has a conversation with Ianto which suggests that she might have feelings for Jack. In "Random Shoes", she is the only one to hear Eugene (although she didn't know that it was him at the time).

At the beginning of "End of Days", Gwen jokingly tells Rhys she is using telepathy on him. Throughout the episode, her emotions are played with as Rhys' life is threatened then taken away, eventually leading a coup with Owen to overthrow Jack and open the Rift, believing it will resurrect Rhys. While ecstatic when eventually Rhys is returned at the price of Jack, who battled with Abaddon and remained dead for days, Gwen stayed by his side for the entire time, unwavering in her belief in him, before he is finally resurrected, and thanks her after she kisses his dead lips. After Jack's disappearance she, along with the rest of the Torchwood Three team, was despatched on a "wild goose chase" to the Himalayas by Mr. Saxon.