There is a peculiar sense of freedom that empty spaces have — you can run through them, jump or stage an impromptu wrestling match on all that open ground. Leverage Dance Theater has conceived a new site-specific dance performance for just such a space. An abandoned school serves as the stage for unOrdinary, a Halloween-appropriate dance concert that draws its inspiration from the architecture of the building. The dancers will move from classrooms to hallways to bathrooms and even across the balconies, so be prepared to follow them through the dimly lit corridors (some limited seating will be available). Audiences are encouraged to get into the spirit of the performance and the season by wearing "creepy and/or decaying" costumes. unOrdinary is performed at 7 and 9 p.m. Friday and Saturday (October 28 and 29) at the Intersect Arts Center (3630 Ohio Street; www.leveragedancetheater.org). Tickets are $20 to $25.