An Acamarian clan which massacred its ancient rivals, the Tralesta, and whose surviving members, including the Gatherer leader Chorgan, were hunted for decades by the assassin Yuta.
Clan Lornak is one of the clans of Acamar III, a world whose people once settled disputes through blood feuds lasting generations. Some eighty years before 2366 the Lornak wiped out the Tralesta in a single raid, the bloodiest act of a long feud between the two.
The clan's history is uncovered in The Vengeance Factor. Many Lornak had joined the Gatherers, the nomadic raiders who left Acamar rather than give up the old ways. When an elderly Gatherer named Volnoth dies suddenly during peace talks, Doctor Crusher finds a microvirus that is deadly only to people with the genetic markers of his clan.
The trail leads to Yuta, a Tralesta survivor, who is about to kill the Lornak chieftain Chorgan when Riker stops her.