Driving through Hubbard’s Cave is one of the greatest cheap thrills in Chicago. Really, it’s just a very long highway underpass, but the “cave” in its name gives it a special tinge of excitement. As do the white tiles on the walls, which are not really cavelike at all.

Normally Canvas has a year to plan a Sub Chroma event. This time they had only two months. As of Friday morning, the viaduct was still empty. On Monday morning, it will be empty again. “That’s the interesting part,” Dahlquist says, “taking a space and, in one day, creating something to be experienced. To me, production is my art form.”