There's a shroud of mystery around performances of Day 19. There's no phone number to get tickets, only an e-mail address for a gentleman from Poland. The Web site for the Scrap and Salvage theater company profiles the credits of creators James Mulligan (Emerson College theater grad) and Rafal Klopotowski (alum of Dutch experimental theater group Dogtroep), and explains that their brand of performance is "site-specific." This means that each show is completely written and designed only after moving into a random space and getting inspired. One past show was performed on a cargo ship. Day 19's venue is behind a black unmarked door on Kearny, a block from Larry Flynt's Hustler Club. It used to be a hardware store and now feels more like a construction site. Before the performance, Klopotowski explains this show was created in less than a month and is still evolving. The results are varied. For a quick 30 minutes, 16 audience members witness bubblewrap sailboats, romantic dancing with light fixtures, and a head that pops up through the floor to eat carrots and scream. These unconnected moments are wonderfully underscored by shadowy figures playing cello, ukulele, and thumb piano. It certainly is a unique theatrical experience (think perhaps early Blue Man Group), but Day 19 feels too much like a very rough sketch of a show rather than a completed vision.