The Dreadlord Nebiat observes a Fissure opening

There are two methods of interstellar travel, technological and magical. Most vessels utilize a Ternus standard FTL drive, allowing them to move roughly ten times the speed of light. This makes travel between systems a long, slow process, often taking weeks or months. It’s impractical to cross significant portions of the galaxy, which limits expansion for Ternus and any other worlds that do not possess a void catalyst.

Void mages can greatly speed travel through the use of Fissures. A Fissure can only be opened in the umbral shadow of a planet, or in the deepest reaches of space. Opening a Fissure requires the use of true magic, channeled through a spell drive, or other powerful eldimagus.

The Fissure fractures reality, creating cracks that vessels can use to slip into the Umbral Depths. These cracks heal as soon as direct sunlight hits them, which is why they can only be opened in the shadow of a planet.

A hellish purple glow leaks through the cracks, shining through from somewhere else. Somewhere with different physics. Vessels that risk entering the fissures tell of enormous shapes swimming through terrible, endless darkness.

Traveling the umbral depths requires gravity magic, as normal engines, shields, and most energy weapons will not function within the umbral depths. Those who enter must posses a map capable of leading them to the area they wish to exit from, though theoretically a vessel can exit from any point in the umbral depths.

Most wise captains order their ships to go dark, and proceed as quickly as possible toward their destination. Gravity magic hurls them through the umbral depths, quietly avoiding many of the nastier threats.

Ships that attempt to run normal engines, or who deviate from the most direct flight path, are usually never heard from again. Those few vessels who explored and lived to tell about it whisper tales about hideous alien monstrosities, but will say little else.

Assuming a vessel reaches its destination, the void mage opens another fissure, and exits back into normal space. After that, vessels reactivate their Ternus drive and head to whatever system they’ve arrived in.