If the Time Agency were still keeping tabs on him, then surely they would have hauled him in by now; he is a glutton, and the 1940s on Earth are his feast of choice.
It started as a money-making venture, and boy had it paid off—the old bait-and-blow trick had reeled in a local agency, no less, giving him enough native currency to set himself up permanently, should he have wanted it. He kind of had wanted it, at least until those same locals started paying more attention than he was strictly comfortable with. Especially to his somewhat anachronistic trappings. He supposes that if they'd been interested in a flying capsule from outer space that they'd not turn the same blind eye to his wrist strap and sonic blaster that most natives were oh-so-willing to.
So he hides the Chula Warship a few centuries earlier, programs his wrist strap to jump a few minutes after he parked it, and gets used to relying on the vortex manipulator to get him around.
It serves its purpose perfectly. And it's easy enough to avoid London. He loves the thrill of a war that's all about meat and spectacle; living, terrified, courageous bodies tearing each other to pieces and worshipping flags and speeches and music.
His second 1941 he visits Turkey, sweat and slouch hats, pheromones thick in the hot air.
The third is spent touring with the brand new USO, and subsequently his new-found penchant for starfucking—and apparently, going native enough to know just who that requires him to seduce—takes him back to New York City where on his fourth round, a brat named Orson gets his cock sucked while he watches himself on the silver screen for the first time. It's a momentous experience, no doubt. And the film isn't bad either, or so he hears.
By the fifth 1941 he's had enough of America, longs for the delicious, earnest repression in British officers, recalling Algy with a great deal of fondness. It's not all nostalgia; in avoiding London he discovers other bits of the Kingdom less brassy than the capital, and in Swansea (lovely name, and yet) hooks up with broad-shoulders and brylcream filling out a captain's uniform very nicely.
Captain Jack Harkness. Lovely name, and yet; he can't help but laugh, and can't even call it coincidence. He's been wringing this year dry of pretty boys and explosions; of course he was bound to collide with his foil's namesake eventually. Can't help but wonder, though, if that surge in vortex energy his manipulator flags in South Wales every time he jumps back to 1941 has something to do with it.
Well, now's the time to find out. That's what he has. A million, a trillion, an infinite number of nows at his fingertips. He takes Jack's hand. It's time to dance.