Bad Girls

"Bad Girls" by M.I.A. was used as incidental music in the Class story The Metaphysical Engine, or What Quill Did, in the final moments of the episode, as Andrea Quill falls over and Charlie and Matteusz discover she's pregnant.

It was the second track by M.I.A. to be used in the series, following Y.A.L.A. which was used as incidental music in the story The Coach with the Dragon Tattoo.