Sartak was once a former Librarian of the Astral Claws but later became a Chaos Sorcerer of the infamous Red Corsairs. Sartak felt that he had followed the easy path for far too many years. Sartak remembered those dark days on Badab, when Huron had poisoned the Astral Claws against the Emperor. Sartak, loyal to his Chapter Master, as a Space Marine should be, followed him into heresy.

Along with 200 other battle-brother he escaped his destruction when he fled Badab Primaris at the end of the Badab War. But the years of reaving had taken their toll on the once idealistic warrior. Like a sleeping man jarred to consciousness, Sartak had opened his eyes to the depravity and corruption of the man once known as the Tyrant of Badab. With this shocking awakening Sartak had realised that there was only one way to make good his betrayal of the Emperor.

He had been found unconscious on the bridge of a White Scars’ cruiser following a Red Corsair raid by the White Scars battle-brother, Arghun. Sartak claimed that he was allegedly through with being a blood-handed reaver and had betrayed his oath of fealty to the Tyrant. If was allowed to infiltrate and find his friend Lothar on Blackheart’s flagship, he would be able to tell the White Scars where the next attack would fall. Brother Arghun and Sartak make their way into the Maelstrom and are eventually captured by the Red Corsairs and brought before their Chaos Lord.

The Tyrant queries Arghun for the reasons he has betrayed his oaths of fealty to the Emperor. Unconvinced of the supposes traitor’s intentions, he orders Sartak to slay the White Scar in order to prove his loyalty. Reluctantly, Sartak does as he is told. After the execution, he seeks out his contact aboard Blackheart’s ship – his friend Lothar. Unfortunately, he finds Lothar in a deadly gladiatorial contest against the reigning Khornate Champion, Crassus. Hopelessly outmatch, Lothar is summarily beaten. As he lay dying, Lothar informs his friend of the Red Corsairs’ next target – the planet Razzia.

Retreating to his quarters, Sartak reaches out to the aether of the Warp and finds the mind of a White Scars Storm Seer waiting for him. Sartak then informs him of the Tyrant’s next target. After sending his astrotelepathic message, Sartak is confronted by Garlon Souleater, the Tyrant’s chief psyker, as well as Blackheart himself. They inform Sartak that they were aware of his betrayal and that they had used him to misdirect the White Scars for their next intended target which was the Imperial world of Santiago, not Razzia.

Facing his doom, Sartak attempts to attack Blackheart but loses both his hands to the deadly Tyrant's Claw for his trouble. Garlon then psychically attacks Sartak and knocks him unconscious. When Sartak finally reawakens he finds himself confined in some kind of container and in utter darkness. His limbs are restrained and tubes have been shoved down his throat. He tried to cast his mind into the Warp, but found that his powers had been suppressed.

Sartak comes to the bleak realisation that he might be sealed into some sort of escape pod and jettisoned into space. But much to his horror, he comes to the sickening realisation that a worse fate has befallen him. Horrified, he realises that he is sealed within a sarcophagus of a Chaos Dreadnought, never to be installed into the nigh-indestructible adamantium shell of a Dreadnought body. Kept barely alive, he is doomed to slowly rot for all eternity. With this shocking revelation Sartak’s sanity flees his once rational mind in a silent scream.