Ariadne "Aria" Cortéz is the last siren. Her enchanting song beguiles all, leading to her imprisonment in a cage. With her legs rendered useless, all she can do is sing until her throat turns bloody and the hope fades from her eyes. In the depths of despair, Aria is lost—until Grand Duke Lloyd Cardenas Valentine gently raises her broken body.

Aria cannot help but see Lloyd as a kindred spirit, for he too has lost all light in his eyes. At the age of only 18, he sold his soul to a devil and murdered his entire family, ultimately turning his sword on the emperor. Lloyd is her savior, so when Aria awakens in the past, she resolves to do anything necessary to protect him and keep his spark alive. She will give him everything—her body, her soul, and most importantly, her voice.