Mary Siringa has finally realized the error of her ways as a spoiled burden to her family. In her search for a job, she runs into Prince Grandiel, disguised as his alter ego, Nepenthes. Intrigued by Mary, Grandiel draws up a magical contract for her to be a maid in the imperial palace and work as his spy. Now, Mary must protect Grandiel's secret identity and comply with the other clauses of her contract, or else her heart will explode! Can Mary keep her true self hidden, or will she die trying?