Amarion grew up in a kingdom beset by monsters and took up the sword when she was just 10. Years later, the king introduces her as the kingdom's strongest knight to Victor Mort, a grand duke from a neighboring empire said to have no equal in battle. Impressed, he proposes to her immediately, which she accepts to receive aid for her people. After the marriage, though, she finds herself with a strange task: taking up a sword and subduing her husband as he sleepwalks. Can she fulfill her duties and help her new husband find peace from his trauma?