(I'm trying to reconstruct this dream fifteen years after the fact from some minimally scribbled notes I found in a box the other day.)
Working at the high school theater, in the lightbooth. Terrorists showed up but I killed some by making a chandelier fall on them.
The stairwells were wallpapered with old horror/science-fiction movie posters.
The rest of the students were taken hostage and I had to free them somehow. The terrorists were forcing them to continue working on preparations for the prom while they were being held. They were all dressed in their formal clothes, too.