Remember that innocent girl who was in a coma for half of Book One? Well, in the beginning of Book Two, we find out that she's the subject labeled "The Betrayer."
Umm. That's not a good sign.
For most of the trials, Teresa pretty much plays the role of temptress. She lures Thomas in, and then crushes him. Then she lures him in again, and she crushes him once more.
Teresa's basically one big mixed message. Want an example? We'll give you Teresa in a nutshell. When Thomas first sees her, she kisses him with tears in her eyes and says: "Get away from me, Tom... all of you need to get... away... from me. Don't argue. Just leave. Run" (20.46).
First things first: this is all an act. Later on, we find out that Teresa and Group B were given specific instructions on how to give Thomas false hope and trust. Even Teresa's mixed messages are… mixed messages.
Because we know she's "The Betrayer," we always kind of wary of Teresa. We can never trust her, no matter whatshe says. Even when she warns Thomas that things will get super bad and that he's going to feel hurt, we simply can't trust her. Hello, she's The Betrayer, meaning she's going to betray someone. And, hello, that person is probably going to be Thomas. And who knows how many times she's going to betray him?
When she explains her relationship with Thomas back in the Maze, she says: "I did what I had to do back in the Maze, and being all buddy-buddy seemed like my best shot... All we had to do was get you here to pass the Trials. And it's either you or us" (50.34).
Ouch. Teresa crushes Thomas with this revelation: not only did she pretend that she liked him back in the Maze, but she's also been playing him the whole time since. Wow-ee, what's going on here?
Nevertheless, Teresa never actually kills Thomas. In fact, she doesn't truly betray him, either: even though she initially betrays him (you know, by crushing his soul, and his head), it turns out that it really was all just an act. The whole "Betrayer" thing? That was apparently all just an act to make Thomas feel like he was betrayed. When Thomas thinks, "She was either a really good actress or had started going crazy. Gained a split personality or two," (45.13), he's actually sort of right.
But still, we'll have to leave you with a Shmoopy warning: nothing is what it seems in these books. For all Thomas knows, Teresa is still putting on an act so that she can unleash some kind of diabolical final scheme. The Ultimate Betrayal.
Teresa herself seems conflicted about her role in the trials. She spends most of the end of the book apologizing to Thomas for what she did, and still, we don't know if we should believe her or not. Thomas, too, has trouble forgiving her.
Still, when she snaps out of her role as "The Betrayer," the first thing she shouts is this: "I'm so sorry Tom... I'm so, so, so sorry. They said they'd kill you if we didn't do everything just like they told us. No matter how horrible. I'm sorry, Tom!" (54.15).
It's hard to know what to think about this. If it's true that WICKED is trying to save the world, and if it's true that WICKED would have just killed them all off if Teresa hadn't played her role exactly as she was instructed to, then Teresa's role is way complicated, and we wonder how she could have acted in any other way. But is she telling the truth? How can we ever know?
Anyway, yeah, okay, she's sorry. Teresa does actually get kind of tired of apologizing by the end of the book: there's only so much she can apologize for, especially given the fact taht she did everything she did (allegedly) to save Thomas's life. When talking about her mission to Thomas, for example, she says: "I kind of accepted it, in a way. That saving you was worth losing what we might've had" (56.35).
If we can truly trust Teresa, then we should accept her apology to Thomas. We can see that saving Thomas despite losing what they had as friends was actually very brave of her. Apologies can only get her so far, but still, she feels pretty darn bad about what she had to do, and her feelings seem more or less legit.