Wormhole

A wormhole is a topological feature of spacetime that acts as a shortcut through space. There is only one known stable wormhole in The Twins, the Origin, which is the only link between the two galaxies, without the Origin it would take hundreds, possibly thousands of years to travel between the galaxies.

Wormholes are not a well understood phenomenon, intergalactic society tends to simply be thankful for the fact that the Origin is stable. Other wormholes rarely last more than 20 standard hours, and will collapse if too much mass passes through them.