While recovering from a severe injury, Wisting receives an anonymous letter. The cryptic content leads Wisting to suspect a possible injustice in an old murder case where a 17-year-old girl was killed, and her ex-boyfriend was convicted这件事情柱子没和任何人说过，因为张小飞告诉他，全部都是家传的东西，柱子心中都已经打定了主意，除了他自己之外，连自己儿子都不传授。