Officio Assassinorum - The Emperor's Knives: The training of an Imperial Assassin is a long and arduous business. Almost every recruit is an orphan, taken from the wreckage of his or her former life among the population of a Death World, Feral World or hive city, and transported to a local Schola Progenium for tutelage. There, they train alongside the youths who will become the foremost agents of the Imperium. Life in the scholas is extremely hard, a relentless grind of physical and mental challenge where only the strongest thrive. Taught to strive for excellence and obedience in all things, the minds and bodies of the recruits are sharpened to a killing edge whilst their spirit learns to embrace the Emperor as master and immortal father.Most of these intense young men and women go on to train as Militarum Tempestus Tempestus Scions, commissars, Sisters of Battle or, in the most unusual cases, Inquisitors. Those of their number who are born killers, however, are instead appropriated by the shadowy figures that haunt each Selection Day. Those recruits are never seen again by their fellows. From that day onwards, their only true friend is death itself.Training starts even as the Assassinorum ships return to Terra, with the Officio instructors testing their prospective pupils mercilessly. The recruits must survive on limited food or air for solar days at a time. They must constantly fight each other in armed and unarmed combat, in conditions of total darkness or blinding light, zero gravity or crushing weight, stifling heat or freezing cold. By the time of their arrival, there may be only a tenth of the prospective Assassins left, or sometimes -- if the instructors deem every recruit to be unworthy -- none at all.Upon arrival at Terra, the surviving initiates begin the next stage of their training. Sailing past the space-borne basilicas, immense queues of pilgrim craft and military cordons that congest Terra's outer orbit, they are carried down into the Temples Assassinorum under the most advanced of shrouding protocols. In subterranean safehouses, these new recruits are divided amongst the hidden temples of the Officio Assassinorum.Each temple has its own ancient ways and mysteries, and each specialises in a different aspect of the art of murder. There are many such temples, some of which are known to the others and some that remain completely secret. There, the initiates train for a full solar decade, labouring under the auspices of Lord Assassins so harsh they make the Drill Abbots of the Schola Progenium look like kindly uncles by comparison.The training procedure becomes ever more rigorous over the years as the temples test each candidate to his or her utmost limits. Days are spent battling with bone-wrenching exercise engines, fighting in deadly bouts or mastering their tolerance for pain. Initiates must survive lengthy courses of psycho-indoctrination and aggressive hypnosis, undergo physical tests of ever-escalating severity, and digest vast quantities of information about the Imperium that will soon be their hunting ground.They must train in the most esoteric of weaponry and steel their bodies against the ravages of endless steroids and stimms. Even then, they have only scratched the surface of their temple's potential arsenal. The hidden orders of the Assassinorum conceal masterpieces of destruction, some of which were devised by the primarchs, Malcador the Sigillite, and even the Emperor Himself. Truly, it is said that each temple houses a thousand deaths and more.