I'm not sure where we were; something like a class trip at the mall, maybe.  My former friend Jenna approached me and at first I was surprised, and then remembered we'd 'made up'.  She was buying a bunch of drinks, and I couldn't understand why.  She said they were going to be really cheap because they didn't have alcohol in them; a dud batch or something.  I didn't understand what she meant until a while later, when it was too late to go buy some.  It seemed like an amusement park.  My old friend Neil Block was there.  I went on a red 'roller coaster'.  It followed a track enclosed by a sort of red tube kind of like a waterslide, though without any slant.  Somewhere there was a waterfall.  There were several breaks in the tubing and there was open air, and we were supposed to find the way off and out, but all the exits looked the same, and the train didn't stop moving.  There was something bad coming, some reason we needed to leave somewhat urgently.