Sentinel Sector

The Sentinel Sector is the Segmentum Obscurus cube of the Sentinel Worlds, a quarantined Eye-neighbourhood of xenos pylons and the Hydra Cordatus gene-seed forge.

Cocytus I and II share the blight with hydra-cordatus-system. Perturabo cracked the Cadmean Citadel in the Heresy; Honsou's warsmith later stole the Imperial Fists tithe stored there.

The Sentinel Sector still matters as a pylon belt that already lost its secret vault. Unofficial summaries keep the Obscurus parent and leave Hydra Cordatus under its system row.