"Something Borrowed" is the ninth episode of the second series of the British science fiction television series Torchwood. It was first broadcast on BBC Three on 5 March 2008 and repeated on BBC Two one week later. The episode was written by Phil Ford, directed by Ashley Way and produced by Richard Stokes. The episode featured the five initial series regulars John Barrowman, Eve Myles, Burn Gorman, Naoko Mori and Gareth David Lloyd plus recurring actor Kai Owen in a central role.

Gwen Cooper is a fictional character portrayed by Welsh actress Eve Myles in the BBC science-fiction television programme Torchwood, a spin-off of the long-running series Doctor Who. The lead female character, Gwen featured in every episode of the show's 2006–2011 run, as well as two 2008 crossover episodes of Doctor Who. Gwen appears in Expanded Universe material such as the Torchwood novels and audiobooks, comic books and radio plays.