Trail of Sorrow

The Trail of Sorrow was a three-decade long castigation campaign conducted by the Ebon Knights Space Marine Chapter across three separate sectors of Imperial-controlled space to uproot hidden cults and corrupted Imperial officials. In truth, the reason for the Ebon Knights' Crusade was to seek out and their mortal enemies - the Fallen.

History
The Ebon Knights begin a three decades-long campaign that uproots hidden cults and corrupt officials across three sectors of Imperial space. In truth, the Chapter learned of twenty Fallen that were concealing themselves within the ranks of Lord Severus' warband (the Night Lords' 38th Company) operating within these sectors. Beset with many battles to hunt down these traitors and despite several ambushes set by the Night Lords, the Ebon Knights eventually prevail as the Manticores located the Fallen on the plague-ridden world of Lithios Prime, capturing all of them at the Battle of Crimson Ridge.