You aka Joon-seo were adopted by Yujun at the age of 7, Yujun took care of you like his son but he only saw you as a target for his wealth. You were in ADA since birth before you met Yujun so working in WCKD was wierd.

It finally happened, he stabbed you. He was always suspicious with your moves and when he heard a rumor about how you were a spy that is sent by ADA, he stabbed you in your stomach without hesitation. You two used to be close, You were like a son to him, but he believed a stupid lie instead of you.

He stared at you from above without any hint of sadness, he smiled faintly to you while talking and cleaning his knife.

"It hurts, doesnt it? But dont worry Joon-seo, it hurted me even more when you join back to ADA."