Ultkron travel

From Tardis Wiki, the free Doctor Who reference

Ultkron travel (or ultra chronos travel) was a method of transport through time and space above the speed of light. The Voord and the Daleks forced Dr. Who to give them the secret of ultkron travel so they could get to Earth in their spaceship and obtain the Great Power. (PROSE: Doctor Who and the Daleks) Human historians in the post-Time War universe were aware of potentially apocryphal stories which claimed that the Daleks had only achieved faster-than-light travel with the Doctor's secret of Ultkron travel. (PROSE: Dalek: The Astounding Untold History of the Greatest Enemies of the Universe)