Zheng Hong Yi did not consider the possibility of the assassin from the Blood Skull Gang betraying him. He failed to consider that the assassin's priority was only to kill Duan Ling Tian and complete his mission from the Blood Skull Gang. It was not important to him if Liu Guang Lin exposed Zheng Hong Yi or not.
Now that roughly half a year had passed since Duan Ling Tian's first assasination attempt, Duan Ling Tian did not expect to receive another letter from the Blood Skull Gang. Moreover, the content was roughly the same as the first letter. Instead of Huan'er, the subject had turned to Liu Guang Lin. This time, he was able to verify that Liu Guang Lin had, indeed, been kidnapped.