After My Mission Failed, the Heroine Went Mad

I was reborn as the true young master in a novel about a fake and a true heir, and I’ll die if I don’t win over the heroine. My progress is at 99%. Once the wedding takes place a week from now, I’ll be able to survive. But on the eve of the wedding, she threatened to call it off unless I went to prison in place of the fake young master she loved and gave him one of my kidneys. Yet when I died on the operating table and they performed an autopsy, she saw my empty abdominal cavity and went mad.