C603 'Who was the murderer? '

Zhang Xin wandered around the restaurant but he did not see the girl or the boy again. He was very dejected. If he had known this would happen, he wouldn't have let them go so easily. However, no one could predict their future.

While walking around aimlessly, Zhang Xin placed his hopes on the investigation by the employees of the restaurant, because if they wanted to poison the restaurant