Flatline

"Flatline" is the ninth episode of the eighth series of the British science fiction television programme Doctor Who. It was first broadcast on BBC One on 18 October 2014. The episode was written by Jamie Mathieson and directed by Douglas Mackinnon.

In the episode, the alien time traveller the Doctor (Peter Capaldi) is trapped inside his time machine and spaceship the TARDIS after the TARDIS's external dimensions get shrunk by two-dimensional extraterrestrial creatures, which he ultimately dubs the Boneless, in present-day Bristol. Assisted by local graffiti artist Rigsy (Joivan Wade), the Doctor's companion Clara (Jenna Coleman) carries the miniature TARDIS with her and temporarily takes over the Doctor's role of trying to protect humanity from alien incursions.

The episode received positive reviews, with particular praise for Coleman's performance.