Watch The Most Unknowable Thing (1999) : Full Movie Online Free Mary Patiernio set out to make a documentary about what she thought might be the last few years of her brother’s life when she found out about his HIV-positive status. However, as the title suggests, things didn’t quite pan out as she expected. Beginning with the video footage from her brother’s surprise marriage to his female chiropractor, following his break up with boyfriend Carlo, the documentary (which was five years in the making), cleverly unwinds to tell one of those stories you simply wouldn’t believe in a fictional film.