Kay Jack was among the bucks first recruited for Black Star Company, and after training and helping to build Vanguard sailed across Ayman Lake. He and his comrades began the excavation of what would become Burnley's Colliery, only to flee the mine site after Captain Fleck Blackstar was injured in an accident. While Fleck recovered, Kay Jack and the other bucks took part in the construction of new ships Lillie and Natalia. Once the ships and Captain Blackstar were ready, Kay Jack and the others sailed back across the lake to continue work on the mine.
Kay Jack and the others later broke away from the mine site to investigate a strange noise, ultimately coming across their lost comrade Gavin. Carrying him back to the mine, they were then forced to flee to the ships as the Lords of Prey launched their first attack against the rabbits. Kay Jack and his comrades boarded Lillie, and helped to defend King Whitson Mariner from the attackers. He survived the Battle of Ayman Lake, and with most of his fellows remained in the new community of Kingston under now Lord Blackstar.