From Cao Xu's agitated reaction and irritable attitude, he could infer that he did not lie about his situation.
"I've casually asked Meng Yiheng and the rest about how they lost their badges. Except for Cao Xu, the other four's statements matched. They claimed that Cao Xu woke them up in the middle of the night and asked for their badges for safekeeping. When they woke up in the morning, Cao Xu had misplaced all of their badges and insisted that he did not take any of them. Other than waking up once to relieve himself yesterday, he had slept through the night," Kang Si said.
"You mean someone controlled Cao Xu and used him to obtain their team's badges?" Na Ken asked as the realization dawned upon him.
"When I brought Lin Ke's team back, they were not even aware that they had lost their badges. They only realized it when I told them so. They had also given their badges to Lin Ke, the student I brought here just now, for safekeeping."