They built it from bits of broken TARDISes in the bubble universe's junkyard, a task which Idris called "impossible". The TARDISes had arrived through the bubble universe rift and been consumed by House and their Time Lord occupants killed, and their body parts were used to repair House's servants. This TARDIS consisted solely of a console (complete with time rotor) and only three walls. Because it lacked a proper shell, the Doctor said it would be very dangerous to fly.
The Junk TARDIS could not draw power from the rift energy in the bubble universe. It worked only because the Doctor's TARDIS, incarnated in Idris, powered it and operated the telepathic circuits.
It was highly unstable in flight, but once the Doctor's TARDIS' shields were down, it materialised in an archived control room in the same spot Nephew stood, atomising him. The Junk TARDIS went missing when the archived control room was deleted by House. (TV: The Doctor’s Wife)
Behind the scenes
- The Junk TARDIS' console was based on a design by Susannah Leah, winner of a 2009 Blue Peter TARDIS console design competition. (CON: Bigger on the Inside)
- The Junk TARDIS was the first TARDIS other than the Doctor's to be shown on-screen since TV: Time and the Rani.
- The Junk TARDIS was released as a playset by Character Options in mid 2011.