A Jack themed episode

Whilst investigating an old, derelict dance hall, Jack and Tosh are transported back to the 1940s, during the Blitz. Owen, Ianto, and Gwen realise, in modern day, that this has happened, and go in search of clues Tosh may have left. Meanwhile, back in the forties, Jack meets a very interesting man. One with the name Captain Jack Harkness...

With the Rift having been opened, people and objects throughout time are falling through it, and being spread across the world. "The thing in the darkness" has finally come, and Jack realises that he is the only one who can save planet Earth from the destruction that "the son of the Beast" will cause.