Hey guys - I'm posting this for SarahSchafer. Based on what she said, I'm thinking this pretty much solves the mystery. At least this one, anyway. . .

Wow. I didn’t even know this website existed! I hope it helps find Amanda.
I’m not sure exactly what you want to know, but I can tell you about the day you guys have been discussing – that Friday when EM2013 saw me standing outside the auditorium with Taylor and Amanda. I had gotten a note in my locker telling me where to go and to hurry because my friend Jamie needed help. When I got there… no Jamie. Just Taylor. We didn’t even have a chance to figure out why the other was there (though it was obvious we were both thoroughly confused) when Amanda shows up, all smiles and sunshine.
Amanda explained this was part of a social experiment she was conducting. She was testing people’s consciences (like, “I know what you did last summer”) or their loyalty (e.g. me) and said she was compiling the results. I don’t know for what, exactly. Why didn’t I ask? You’d think I would be kind of P.O.d about the whole thing, for getting duped and all. I was at first, but then Amanda made me feel it was kind of an honor that she picked me. Like I was special, chosen. Yes, I know that sounds lame but it’s the only way I can explain it.
So I’m guessing when she read the note in class a couple of days earlier it was part of a different “trial” as she called it and just part of her little science project.
