Captain Jack Harkness is a fictional character played by John Barrowman in Doctor Who and its spin-off series, Torchwood. The character first appears in the 2005 Doctor Who episode "The Empty Child" and subsequently features in the remaining episodes of the 2005 series as a companion  to the series' protagonist, the Doctor. Subsequent to this, Jack became the central character in the adult-themed Torchwood, which aired from 2006 to 2011. Barrowman also reprised the role for guest appearances in Doctor Who in its 2007 series and 2008 series, as well as the two part special The End of Time.