One of them, Milk Run, was in a special room and came with instructions, which I didn't bother to read, and so was soon walking down a completely dark corridor and round two sharp bends that cut off any light at all from outside. (I ran into the wall on the second bend.) After that, I staggered forward for a while towards a pale glow, hand trailing the wall and feeling for every footstep in case there was a step up or down in front of me. I'd been doing that when someone behind me hissed, "Hey, you people are *in* the exhibit. Come back here." And someone else giggled, "It's like watching zombies stagger around."
I made it back, with considerable help, to the bench from which you are actually supposed to observe the pink glow. As our eyes gradually dark-adapted over twenty minutes or so, the slight sensation of light turned into a deep red rectangle that seemed to hang in mid-air, white highlights to one side of it and a feeling of a frame hanging in a different plane so that it did not enclose the work, but rather set it off as an accent.
It was an impressive piece of art. Pictures don't do it justice, since you're not in the dark, but here is one, FWIW. But much more impressive was watching the next wave of non-dark-adapted zombies arrive, and then the next and the next. Each time there was a 'thunk' as at least one of every party walked into the wall in the corridor, and then the strange stagger, similar across all but always different, as the new arrival, completely in the dark, tried to orient themselves using the faint glow. At the back, with our adapted eyes, we could now see them very clearly, silhouetted against the artwork. Some staggered and tried to get out through the light source of the piece. Some felt along the wall. Some had read the instructions and had some idea there was a bench at the back and just needed encouragement. One couple kissed and I briefly entertained the idea we were in for a very naughty shadow play, but they got bored and staggered out after a while. A few hopeless sad cases used their cell phone lights, which of course risked burning our retinas so we shouted at them.
STB said, "You can do this in art. If this was a science experiment you'd never get the IRB to okay doing this to people."
And I managed to get a hot dog from a vendor outside afterwards.