Thomas has shown immense bravery so far, so why does Thomas run from Teresa? (Chapters 26-28) (Pages 164-184)

Thomas runs from Teresa because she is communicating with him mind to mind.... talking to him inside of his head, as no one else can hear. Thomas couldn't believe what was happening..... so he ran.

He put his hands up to his ears, squeezed his eyes shut. It was too strange; he couldn’t bring his rational mind to accept what was happening. My memory’s fading already, Tom. I won’t remember much when I wake up. We can pass the Trials. It has to end. They sent me as a trigger. Thomas couldn’t take it anymore. Ignoring Newt’s questions, he stumbled to the door and yanked it open, stepped into the hall, ran. Down the stairs, out the front door, he ran. But it did nothing to shut her up.

(Page 105/ my copy)