In the underhive of Bellaphon III something stirs, a malign presence that has lain dormant for generations.
In response to rumors of warp disturbances, and mysterious disappearances Inquisitor Amberley Vail of the Ordo Xenos embarked upon investigations in the main under warrens of Tarsis Ultra, the capitol hive of Bellaphon III.
Last transmissions from the Inquisitor are garbled, what little that can be deciphered by the Astropathic choir speak of untold horrors beyond the imagining of mortal man, and of cults whose devotion and loyalty puts shame tothe Imperial Creed. Few outside the Inquisition have knowledge of what could be the cause of such devotion, but to the Ordo Xenos the signs are eerily familiar.
The Ordos has little choice but to resort to its finest and deadliest weapon. The battle brothers of the Adeptus Astartes, those who make wear the sigil of the Inquisition in place of their chapter marking, are recruited, for a time, from the many and varied chapters of Space Marines. Exemplars in the arts of killing all forms of foul Xenos, clad in the Black Power armour, and armed with the finest instruments of death found in any Imperial Arsenal you are the emperor's finest
You are the Deathwatch

The Imperial world of Caladan is a world of moderate significance, deep within the Hades Rift. A planet of azure oceans and tropical islands, there is little to interest outside parties as the planet has low strategic value to the foul Xenos who infect the sub-sector. What is clear is that shortly before all Astropathic communication was abruptly cutoff the Planetary Governor demanded urgent assistance from the Astra Militarum.
The Cadian 92nd, fresh from a campaign to purge Heretical worshipers of Chaos have been re-routed to join ten other regiments in restoring order to the isolated Ocean planet.
The players, under the command of Captain Stromm, Second Company, find themselves tasked with leading the assault to retake the Governor's palace.
It is the 41st Millennium and in the grim darkness of the far future, there is only war