Unmistaken Child is an engrossing account of the search for the transmigrated soul of Lama Konchog, a Tibetan Buddhist holy man who died in 2001 at age eighty-four, leaving his young, insecure, and sensitively photogenic disciple, Tenzin Zopa, with the unwanted assignment of conducting the search, combing the countryside for signs of an extraordinary one-to-one-and-a-half-year-old. An astrological reading beforehand affords him a couple of John Edward-like alphabetical clues, a ninety-five-percent probability of the father’s name beginning with an “A,” and a letter combination of “ts” in the likely locale, sending him off on foot to the Tsum Valley where he himself originally came from and first met his master. So many documentaries these days — Food Inc., The End of the Line, Under Our Skin — are essentially just illustrated lectures, talking-head experts with visual aids. This one, the first effort of Nati Baratz, is a bona fide document, granting privileged access to an arcane process that stretches over five years, searching, finding, testing, verifying. It doesn’t go into the mysteries of reincarnation, only the (so to speak) missing-persons detective work. The utilitarian video image is by nature somewhat unappreciative of the physical world, but is itself a document of the difficulties of the shoot.