A space/time conduit was an access point for either time or the time vortex. It had the appearance of a mass of grey sky, the very matter of time.
The ancestors of the Chronovores created the Darkheart as a space/time conduit, which was capable of sending time energy to any point in space or time. They constructed this from dwarf star alloy from a neutron star, shaping the alloy into a planet near the star, the mass being divided by a dimensional bridge. This prevented the star from collapsing into a black hole. (PROSE: The Dark Path)