After some investigation and tracking, Xie Fangze finally found out that the place where the potion first appeared was a military school, and this school was the school attended by his guide brother who was ten years younger than him.

In order to further uncover the truth behind the incident, Xie Fangze made a prompt decision, applied to his superiors, and took the position of instructor at the school.

As expected, not long after Xie Fangze was transferred to this school, he keenly noticed that one of the guides here was behaving unusually strangely.

As the investigation progressed, Xie Fang learned that all of this was planned and implemented by the guide's father.

And that guide was just a puppet controlled by his father.

The guide's father, Zhou Chengde, used to be a teacher at the Research Institute. As a sentinel, what he wanted most was that the sentinels could get rid of the guide's guidance. He believed that sentinels should be strong and did not need cowardly guides.

Because his experiment required the cooperation of a guide to provide guide factors, he was expelled from the research institute for disrespecting the guide and even attempting to force the guide to do experiments.

But he did not give up the crazy experiment. Since other people's guides didn't work, he would use his own guide to experiment.

Unfortunately, his wife Wen An is only a C-level guide, and her guide element is simply not enough to support him in conducting experiments.

So Zhou Chengde forced his wife to get pregnant again, but things did not go as he wished, and the child his wife gave birth to was a sentry.

Zhou Chengde, who was angry and had evil intentions, after careful planning, spent a large sum of money to bribe a greedy nurse.

Without anyone noticing, he swapped his own child, who was a sentry, with another innocent guide child.