The brothers grow greedy, and, after plundering their father's Ages, they trap Catherine on Riven. When Atrus returns to investigate, the brothers strand him in a D'ni cavern before they themselves are trapped by special "prison" books. Through the help of a Stranger, Atrus is freed and sends his benefactor to Riven to retrieve Catherine from the clutches of Gehn.[1] Sirrus and Achenar are punished for their crimes by being imprisoned in separate Ages until they reform.[2]