Torchwood - Season 1 Episode 12

Jack and Tosh investigate when there are reports of music coming out of nowhere in an abandoned dance hall. While in the building, a temporal rift sends them back to 1941, but they soon realize they can't get back to their own time. At least not without Tosh sending those in the present day the necessary equations to make it happen. While at the dance hall, Jack runs into someone he knows, an American RAF pilot by the name of Jack Harkness. In the present day, Owen, Ianto, and Gwen are working to get them back. Owen wants to open the rift and try to get Diane Holmes back as well, but opening the rift could destroy the city. The dance hall manager, Bilis Manger, seems to have little trouble going back and forth in time, however.