Icebreaker trilogy

"Petrel is an outcast on the ancient ship, an icebreaker, that has been following the same course for 300 years. In that time, the ship's crew has forgotten its original purpose and broken into three warring tribes. Everyone has a tribe except Petrel. Nicknamed the Nothing Girl, Petrel has been ostracized ever since her parents were thrown overboard as punishment for a terrible crime. But Petrel is a survivor. She lives in the ship's darkest corners,...

While Gwin, a Fetcher, and her family defy the Devouts by sharing song and story, the Oyster's crew and the Sunkers continue fighting to bring light back to the dark world.