Cruciform

The Cruciform existed during the Last Great Time War. The Dalek Emperor took control of the Cruciform during, while the resurrected Master was present. The Master was so scared, he ran away and used a Chameleon Arch to turn himself into Professor Yana and hide near the end of the universe. (DW: The Sound of Drums)

The Tenth Doctor stated that the Cruciform fell at the same time that Gallifrey was burned. (IDW: The Forgotten)


 * The Cruciform hasn't been confirmed to be either a location, a weapon, a ship or some kind of object. It has only been mentioned, not described. The word cruciform, of course, means “cross-shaped”.

Behind the scenes

 * The Crucible mentioned in the filming of The Stolen Earth has been said to be in no way connected to the Cruciform.