The two young women and middle-aged man in Danielle Dean’s new nine-minute film, playing in Commonwealth & Council’s main gallery, look like hospice workers. They’re wearing colored scrubs and they show up in a run-of-the-mill Houston apartment, and set up sterile-looking equipment. Except they use that equipment to do science experiments, or, maybe, to make Hexafluorosilicic acid, the compound that’s converted into aluminum fluoride. Dean titled her film Hexafluorosilicic, and her characters seem both complicit and conflicted about whatever they’re doing. Pixelated advertising imagery sometimes flashes across the screen and something frightening seems to be lurking behind a doorway the characters hover around.