Haran Serpens was a well known Magos Biologis, a Tech-adept of microbiology and cellular replication within the Adeptus Mechanicus. After his untimely death, his identity was usurped and used as an alias by Fabius Bile for a variety of purposes, such as trading with unsuspecting counterparties, and, in a notable instance, to confound and corrupt Apothecary Majoris Caecus of the Blood Angels Chapter. Bile thus managed to set foot on the Blood Angels' homeworld of Baal and steal a vial containing the blood of the Blood Angels' Primarch Sanguinius. Bile planned to use the genetic information stored in this sacred relic of the Blood Angels Chapter to pursue his continuing quest to create more perfect Astartes than the Emperor.
Through Bile's manipulations, Caecus was duped, and only managed to create monstrous, mutant clone-Astartes known as "Bloodfiends" who were consumed by the genetic curse known as the Red Thirst. These creatures were a shattered mirror reformed in the image of a Blood Angel, but lacked any of the qualities that might be thought of as human. The mutations that cursed the gene-seed of the Blood Angels had been enhanced by the machinations and Chaotic tech-heresy of Fabius Bile, and with each drop of blood they consumed, the thirst that dominated the Bloodfiends grew stronger. The mutants broke free from the confines of Caecus' laboratorium and began to run rampant through the sacred halls of the fortress-monastery of the Blood Angels. During their rampage, Bile managed to steal a glass vial that Caeucus had carried back from the Chapel of the Red Grail -- a measure of the mingled blood of a hundred centuries of Sanguinary Priests and the Primarch, the raw vitae of the Chapter.
During the Bloodfiends' rampage, a small group of the bloodthirsty mutants assaulted the sacred Chapel of the Chapter's fortress-monastery. Brother Corbulo raced to the Chapel to confront the creatures. He knew exactly what it was the beasts wanted, and he bellowed out a denial, charging in a headlong rush to meet such embodiments of corruption. The creatures swarmed Corbulo as the Sanguinary Priest carved into them with his Chainsword Heaven's Teeth. But the largest of the Bloodfiends, a massive brute easily the size of an Astartes in Terminator Armour, threw itself towards its target -- the Red Grail and the precious blood of the Primarch it contained. The Bloodfiend seized the holy relic and then tipped the contents of the cup into its open mouth and drained it to the dregs. Now that the beasts had tasted the blood of the Primarch, they only craved more. In the aftermath of this desecration, Bile had achieved his goal and escaped from the Blood Angels' homeworld with a sample of the precious vitae of their Primarch to continue his experiments.
Having finally secured their homeworld against Bile's mutant-creations, Lord Commander Dante assigned Sergeant Rafen the vital mission of recovering the missing phial that contained the blood of their Primarch that had been secreted away by Bile during the Blood Angels' conclave. Rafen was to recover this most precious of resources and execute the one who stole it for his foul transgressions. Rafen futilely followed the trail of Fabius Bile aboard the Strike Cruiser Tycho for some time, but the trail had gone cold. With the help of Sergeant Noxx of the Flesh Tearers Chapter, the two noncommissioned officers were able to combine their squads and redouble their efforts in tracking and hunting down the elusive Bile. Eventually, the Clone Lord's whereabouts were traced to a powerful Adeptus Mechanicus Magos by the name of Matthun Zellik who had prior dealings with Bile in his usurped identity as the Magos Haran Serpens, the same alias used by Bile to infiltrate the Blood Angels' fortress-monastery on Baal. The joint Space Marine strike force attacked the vessel Archeohort, an ancient and unusual excavation ship solely manned by Servitors and members of the Skitarii.
Rafen and Noxx were able to take advantage of a turncoat within Zellik's retinue, and were able to make their way to Zellik's trophy room. They were able to force the Magos' surrender when they began to smash and destroy the relics he had recovered during his long career. With the vessels Archeohort, Tycho and the Flesh Tearers' vessel Gabriel, Sergeat Rafen and his Battle-Brothers traveled to the world of Dynikas V, a world in the Ghoul Stars region, where Magos Zellik had last had dealings with "Magos Serpens." This unusual world had fallen victim to the predations of a tendril of a Tyranid Hive Fleet, but do to unusual events, somehow the oceans remained intact. Within the oceans of the ravaged planet lurked several aquatically evolved Tyranid bioforms, who were now leaderless without a Hive Mind to control them. Thanks to a captured Zoanthrope Bile "modified", the pheromones produced by the creature were used to confuse the Tyranids and hide the existence of Bile's facility from their senses.
Sacrificing Magos Zellik's ship, Sergeants Rafen, Nox and their men descended upon the planet using a submersible to approach Bile's suspected base of operations. But the mission soon went awry when the Space Marines were forced to battle enormous Tyranid creatures that rivalled the mighty Ice Krakens of the Death World of Fenris. During their nautical battle, Rafen was somehow separated from his allies and managed to float to the surface where he was captured by Bile's enhanced, mutated slaves and brought to the Clone Lord's laboratorium within his bleak fortress complex. Disarmed and strapped to an examination table, Rafen had a strange maggot implanted into his body that bound itself to him and was taken before Fabius Bile himself.
The Clone Lord began to espouse his grand scheme to use the highly pure blood of Sanguinius to help him in his most audacious scheme: obtaining the complete genetic code of the Emperor of Mankind and creating a replicae (clone) of him -- that Bile would control -- with all of the Emperor's psychic powers and other attributes, though none of his moral sense. For millennia, Bile had been collecting body parts and genetic material from captured or killed Space Marines to further this project, the ultimate goal of his quest for human perfection begun so long before. Sanguinius' blood, carrying a purer strain of the Emperor's DNA than that of the genetic material reaped from the gene-seed organs of countless Astartes, was a huge leap forward for Bile's ambitions. Though severely wounded and weakened from his recent ordeal, Rafen managed to attack the wretched Bile and tear out his throat with his teeth, killing him.
However, unbeknownst to Rafen, Bile was not actually dead. Following this assassination, Rafen was taken to a bizarre arena where he was forced to take part in a race against mutants and other captured Astartes, lest he be killed. During this contest, Rafen saw Bile in the audience, somehow still alive. During this contest, Rafen encountered the bellicose Tarikus, a captured Doom Eagles Space Marine, and conspired with him to effect an uprising against the Clone Lord. Meanwhile, Sergeant Noxx had taken charge of the joint Space Marine strike force and effected an assault upon Bile's fortress complex. During the ensuing battle Brother Ceris, a Librarian in Rafen's squad, psychically contacted his squad leader and bade him to assault a strange Warp signature to prevent Bile from effecting his escape. This strange Warp signature proved to be a captured Zoanthrope that had been harvested by Bile and bent to his will to create Warp portals and ward away the other Tyranid bioforms on the planet. The Zoanthrope welcomed oblivion at the hands of the Blood Angels Sergeant.
During the battle that ensued, Fabius Bile was killed no less than four times. The truth of the matter was revealed to Rafen and a handful of his allies when they encountered a pair of clones of Bile; apparent copies of the true Fabius Bile who was not even on the planet. Though unfortunate, when confronted, one of the Bile clones did possess the coveted phial of Sanguinius' blood. When Rafen fought the last Bile clone he managed to take it from the clone and inject it into himself, temporarily attaining enormous strength and power from the blood of Sanguinius. Bile had told Rafen that he did not need the blood anymore, as he had analyzed it already, and had grasped its genetic secrets. The Space Marines then effected their escape by teleporting away from Dykinas V while the Tyranid bioforms ravaged Bile's fortress complex in the absence of the captured Zoanthrope who had been keeping them at bay.
Following these events, the presumably "real" Bile is still alive and well on an Eldar Crone World. His knowledge of the Emperor's DNA is intact, but the replicae project has suffered major delays thanks to the Blood Angels and Flesh Tearers' actions. He was offered an alliance with the Daemon Prince Malfallax to take revenge against the Blood Angels, although it is not currently known whether he accepted the offer.
- Red Fury (Novel) by James Swallow
- Black Tide (Novel) by James Swallow