Gwen was a Cardiff Police Constable when she stumbled across a secret Torchwood operation which involved the death of several people. She joined Torchwood at the invitation of Capt. Jack who valued her empathic nature and ability to see beyond the facts.
As a Torchwood Operative she provides an essential foil to Capt. Jack, although her personal agendas often interfere with her duties. Her actions and descisions are often guided by her desire to protect her live-in boyfriend, Rhys, and her disruptive affair with Owen Harper.
(Author: DeanoDeano)