Jack Harkness (The Time of Clara)

"Wait... only one heart. Might be a Zygon, Martha, the antidisguise gun. That's no Doctor."

- Jack to Martha in "Goodbye Gallifrey"

Jack Harkness was a human who worked for Torchwood. After meeting Alonso Frame, thanks to the Doctor, he eventually returned to Torchwood, where he, Martha Jones, and Mickey Smith continued their work. Later on, they met Clara Oswald and Ashildr, who they had further adventures with.

Career
At Torchwood, Jack worked with Martha Jones and Mickey Smith to pull in a TARDIS that they had located. Upon pulling it in, they discovered that its inhabitants were not the Doctor and whoever he was traveling with, but instead, Clara Oswald and Ashildr. Martha went to confront them. Later on, as they discussed whether or not they could trust the duo. However, they were interrupted by Zyger, a renegade Zygon who was part of the Cult of Zygor, who was also disguised as the Twelfth Doctor, whom Clara recognised. Deducing that he was a Zygon, Jack used an antidisguise gun to unveil his true identity. When General Zygina and the rest of the cult revealed themselves, Clara and Ashildr launched into battle. Jack, Martha, and Mickey watched until they, too joined the conflict. After killing two of the Zygons, Jack used the gun again to lock Zygina and Zyger in a permanent form. However, Clara disintegrated them. ("Goodbye Gallifrey")

Personality and traits
Jack is flirty and friendly, but when times call for it, can be the most serious member of the team.

Behind the scenes
Jack is portrayed by John Barrowman.

Series 1

 * "Goodbye Gallifrey"