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.