It can be a terrible thing for a knight to find himself sworn to a corrupt, evil, or otherwise unfit lord. The morally flexible knight may find he thrives in such conditions, but for those who take their knightly vows more seriously, they find themselves in an untenable position. They can continue to serve their lord, and accept that they likely will end up doing terrible acts in his name. Or they may kill themselves. Theirs oaths leave no other options.
There is, however, a third option. An equally terrible option for an honorable knight: forswear their oath and abandon their liege.
The Twicesworn are an ancient organization offering absolution to those knights who would break their oaths. Sometimes hunted, often reviled, and rarely accepted, the Twicesworn swear new oaths to the realm. They swear to protect the peasantry, particularly from injustice and cruelty at the hands of nobles.
Life for a Twicesworn knight is lonely. Even those he is sworn to protect fear and mistrust oath-breakers, so the only camaraderie he knows is that of his brothers and sisters. Many of them chose to become Twicesworn as an alternative to suicide, but end up finding themselves driven to it regardless.