Zhang Xi took her own bottle, and noticing that Xia Enci's and He Ling's had yet to be delivered, she took advantage of the moment when no one was looking to slip the medication in.
It was some sort of anti-depressant, capable of effectively lifting a patient's spirits.
However, a person with normal emotions who took it would experience significant emotional turmoil and unease, becoming easily angered and irritable.
If two people who were already not particularly reserved emotionally were to take it, and then argue a bit, the likelihood of a fight breaking out was high.
And He Ling and Xia Enci were exactly such emotionally unstable individuals.
Once they started fighting... Zhang Xi could take the opportunity to get Xia Enci's phone and delete the video inside it.
Those who fought at summer camp would at the very least face serious disciplinary action, or at worst, be directly expelled from camp.
