There’s no explanation how or why Jack Harkness is in charge of of squadron (well 15 men) in Lahore in 1909. Probably working for Torchwood (should be, according a later ep), I guess he’s on an extended mission? Detached assignment? Who knows, it isn’t brought back up again.

You’d better not call any fairy folk while I’m gone!

(Jack’s ex girlfriend does just that and dies after years of investigating them).