Warpspace

Warpspace was a "secret passage" through normal space that allowed for faster-than-light travel and time travel. Openings to warpspace resembled cracks, and ships travelling through would vibrate and could experience hyperspatial turbulence.

For ten years after the Cyber-Wars, 10,000 Cyber Ships hid in warpspace above "planetoid X" waiting to be activated and change the outcome of the war. (AUDIO: Last of the Cybermen)

Humans travelled through warpspace. The colonists of the Elysium system, having survived a theoretically un-survivable situation, believed the Artifact affected warpspace and actually saved them. This led some of the colonists to believe the Artifact was God. (PROSE: Parasite)