Clara and her sister Isabella were engaged on the same day: one married Derek, the werewolf leader, and the other married Lucien, the fallen vampire lord. In her past life, Clara and Isabella suffered an accident and were reborn, returning to their engagement night—only to find Isabella had also returned and switched their fates, preventing Clara from suffering the same tragic end. After marrying Derek, Clara used her reborn memories to warn him of an impending deadly ambush and, leveraging her family's business power, supported his army, earning respect at Blackthorn Manor. Isabella gradually fell into Lucien's lies and political traps, but Clara grew stronger and wiser.
