Quote Originally Posted by smallskenobi View Post
i think at one point, Kelly was the traitor. after Tommy's death she had a change of heart, so she stopped contacting the mallers. so the mallers send in pippin as a backup. once kelly got some alone time with pippin in the guard room, she then questions him to see if he's there to spy, or if his story about him escaping is true. she then finds out he is there to spy, she's been on guard duty for a while, she had more than enough time to come up with a plan. listening to pippin's final words, he seemed surprised at who and what that person was doing. it would make sense for it to be the person he had the long talk with.
This is my favorite explanation so far, and it supports my belief that Kelly was the rat, but decided to have a change of heart, and wants to hide her past actions. Nicely said!