Characters: Jack Harkness

Captain Jack Harkness is a fictional character played by John Barrowman in Doctor Who and its spin-off series, Torchwood. He first appears in the 2005 Doctor Who episode "The Empty Child" and reappears throughout the rest of the 2005 series as a companion of the ninth incarnation of the series' protagonist the Doctor. Jack goes on to become the central character in Torchwood, an adult-themed spin-off of Doctor Who. He returns in the 2007 series of Doctor Who, reuniting with the tenth incarnation of the Doctor, and returned again for the 2008 series.

In the programme's narrative, Jack is a time traveller and former con man from the 51st century. In contrast to the wiser and older Doctor, Jack is a man of action, more willing to see the hands-on solution to the problem at hand. As a consequence of his death and resurrection in the 2005 series finale of Doctor Who, the character becomes immortal, a lasting change throughout his appearances in both series. Jack eventually becomes the leader of Torchwood, a British organisation dedicated to combating alien threats. Adding another layer to the character is a vague backstory which is gradually revealed as both programmes progress.