A region of the Al-Gheri sub-sector, the Prastian Straits are a series of star systems linked by a many-branched, convoluted series of of warp conduits that are famous for throwing ships off course.

Catastrophic losses are no more regular than average, but ships often arrive at the wrong system, having taken the wrong path through the aether of the Straits. There are estimated to be thirteen entrances and exits to the Prastian Straits, eight in systems incapable of supporting life and five populated systems. Of these five, three are Imperial - Marax, Rielsprit, and Colossus - and two lie outwith Imperial control. Ter is home to a Schest infestation, and Maalachai is ruled by the Pirate Brigands of Lord Captain Hagen Bloodoath. Due to the risks of exiting in the latter two systems, travel between Marax, Rielsprit, Colossus and the rest of the sub-sector is not undertaken lightly.