Space Wolves - Lost Companies: First and foremost the most legendary amongst the Lost Companies of the Space Wolves is the fabled 13th Great Company. During the dark days of the Horus Heresy, the entirety of this company supposedly vanished into the Warp in pursuit of the retreating Traitor Legion forces. Far beyond the eyes of the Imperium the 13th Great Company continued to hunt the Traitors throughout the Eye of Terror for the next ten millennia, only reemerging at long last during Abaddon the Despoiler's 13th Black Crusade, ever in pursuit of the oathbreakers. The first and most obvious way in which a Great Company becomes lost is the damnation of becoming lost in the Warp. This usually occurs when the vessels of a Great Company are caught in a deadly Warp Storm or dragged to their doom by a predator of the Empyrean, their bodies and souls trapped within the Warp for all time. Their vessels sometimes surface ages after their disappearance as ghost ships or as part of a dreaded Space Hulk, chilling reminders of the perils of Warp travel.The second way in which a Great Company becomes lost is by choice. This seems strange to some in the Imperium but to the Space Wolves it can be a matter of pragmatism. Sometimes a Great Company will find itself so far afield that to return to The Fang would take standard years, if not solar decades. Occasionally a Warp Storm might block any hope of return. In these cases some Wolf Lords choose to forgo any attempt at a return and simply soldier on, campaigning until the last Space Wolf falls. At other times a Wolf Lord may have a fundamental disagreement with the current Great Wolf, and rather than continue in his service, will opt to take those warriors and vessels loyal to him and leave to fight the enemies of the Emperor in whatever way he chooses fit until his warriors' strength is expended.The last and most insidious way a Great Company can become "lost" is to turn their backs on Russ and the Allfather, becoming pirates, Renegades and Traitors. The worst cases are when a Lost Company wholly embraces the corruption of Chaos. No Chapter speaks easily about those of their number who have fallen to the grip of damnation, but it happens to them all, as only the secretive Grey Knights of the Ordo Malleus can claim to have never had an Astartes fall to the temptations of Chaos. Traitor warriors are hated and reviled by the rest of the Chapter and no sacrifice is too great to see these Heretics destroyed and the honour of the Chapter restored. Several notable examples stand out in recent Chapter history. One is the capture of the Space Wolves' Strike Cruiser Wolf of Fenris by the Red Corsairs Chaos warband at the Battle of Parenxes, sometime after the Badab War. During the battle, the Red Corsairs managed to sway a number of the Space Wolves crew to their side. These Oathbreakers turned against their brothers and helped the Chaos Space Marines seize their own vessel. In reward for their treachery, the turncoat Space Wolves were given command of the Wolf of Fenris and have continued to sail under the command of Huron Blackheart and the banner of his Red Corsairs ever since.More recently a small Pack of Grey Hunters from the Blackmane Great Company chose to go rogue, stealing a Ryza Pattern system-runner called the Hlaupnir. This Pack of six Battle-Brothers then sailed out on their own. These Grey Hunters have chosen to hunt down leads on a secretive organisation within the greater Adeptas of the Imperium known only as the Fulcrum -- a group they believe is conspiring to destroy the Space Wolves Chapter. If they prove successful in hunting down and eliminating this most dire of threats, they will no doubt be welcomed back to The Fang with open arms, and glorious sagas will be sung of their great victory, their boldness and bravery. Should they fail in their self-appointed task, they will die as Oathbreakers, their names stricken from the sagas of the Chapter. Yet such a decision is not unusual, for the desire to be the outrider, to strike out on one's own recognizance has forever been ingrained amongst those who bear the Canis Helix. This ultimate gamble of not only life, but honour and legend is one that few Sons of Russ can resist.