In the episode, the alien hunters Jack Harkness (John Barrowman) and Toshiko Sato (Naoko Mori) are brought back in time to a Cardiff dance hall in 1941.
In the present, the rest of the team come to realise Jack and Toshiko are missing in time from photographs taken during the dance, and also determine that the Rift is the only way to bring them back, though Ianto believes it to be too dangerous.
Unknown to them, Bilis is also present at the dance hall in 1941 and has attempted to alter and change the messages that Toshiko is leaving for Torchwood.
In the Torchwood Series 1 DVD extras, John Barrowman sings the song "Anything Goes" with the band live on the set providing music, adding Torchwood-specific references.
They were first shown on the same day as the first broadcast of "Invasion of the Bane", the first episode of the Doctor Who spin-off The Sarah Jane Adventures.