House Dihanur and House Rokat were in a bitter blood feud. The Dihanurs sent assassins to kill every Rokat that existed, regardless of age and gender. The revenge was in retaliation after one of the Rokats killed Palaq Dihanur, the patriarch of their clan, severed his head and displayed it in a public place. The Dihanurs' goal was to force the Rokat family into extinction
The Dihanurs had already killed a slew of Rokats in countries like Janaal and Bihan, that are less likely to provide support for blood feuds. They used unmagic, which made them invisible and undetectable. The magic could also be used to get rid of, literally destroying, warding spells and the like. Thus they were able to sneak in to heavily guarded and protected areas in order to murder. When quite a few Rokats were offered protection in the Keep of Duke's Citadel, one of the most magically protected areas in Summersea, they were able to infiltrate it, and were barely stopped.
The assassins killed men, women (regardless of whether they were born Rokats), and children. They killed wives in case they were pregnant with more Rokats.
Capture and death
The Dihanur perpetrators and the unmage were captured using an unmagic net woven by Sandrilene fa Toren, an ambient thread mage who had the rare power to weave magic. It was the originally the plan to catch them and put them to trial, but Alzena grabbed Pasco Acalon and threatened to kill him if Sandry did not release them. Thus, Sandry was forced to kill them using the unmagic net in order to rescue Pasco.