Trap Door is emblematic of the streetwise, no-holds-barred brand of off-Loop theater. A risk-taking, emotionally high-voltage company that has somehow stayed afloat (despite performing in a converted garage hidden behind a Bucktown restaurant), Trap Door concentrates on plays with a social or political bent. Many tend to be original works or decidedly noncommercial, provocative pieces by rarely produced cerebral artists, many of them European. (The show AmeriKafka, inspired by writer Franz Kafka and his visit to a performance by a Yiddish theater troupe, even featured a brief X-rated puppet show.) Prepare to be challenged: Theater doesn't get any more up close and personal than this.