The second half of the Oathbreaker story opens at the assassins' stronghold, Triune, as Aron and his sworn comrades try to find peace in a world on the brink of war. Dari and Stormbreaker grow closer as they search for Dari's missing twin; Nic and his captors find it harder to conceal their secrets; and Aron must decide whether the bond he keeps to his family will prove stronger than the oaths he has sworn to his closest friends.