Man and TQ4 perform live on this episode : The TARDIS (/ˈtɑːdɪs/; acronym for "Time And Relative Dimension In Space") is a fictional time machine and spacecraft that appears in the British science fiction television series Doctor Who and its various spin-offs. Its exterior appearance mimics a police box, an obsolete type of telephone kiosk that was once commonly seen on streets in Britain. Paradoxically, its interior is shown as being much larger than its exterior, commonly described as being "bigger on the inside".