Captain Jack Harkness was a fifty first century human. They were a bit more advanced than their younger century humans. They have been evolved to produce more highly evolved pheromones, which make them more sexually attractive than baseline Humans, and they were more sexually free. Which explained a lot about Jack's choices. He'd do anything with a postcode.

Jack was also in charge of a group called Torchwood Institute. More specifically, Torchwood Three. Which is where he just walked into. After he went down the lift, he headed through the doors to find his 'assistant' Ianto Jones.

He had just gotten back from being thrown into the Rift. He'd met the real Jack Harkness. He looked around, and didn't seem to see Ianto.