Brian Springer derived the curious title of his perplexing documentary The Disappointment: Or, the Force of Credulity from the name of an American ballad opera pseudonymously composed in 1767. Mocking the contemporary vogue for treasure hunting and spiritualism, among other Colonial follies, the two-act satire so inflamed the citizenry that they cancelled its debut in a Philadelphia theater by burning it to the ground. Or so we are told by the aptly bizarre narrator of this singularly strange film: a limestone sculpture combining insect, reptile, and amphibian anatomies that may or may not have been discovered at the end of the 19th century on the Missouri farm of Kate Austin, a legendary anarchist who may or may not have kept a diary-—that may or may not be buried in the vicinity of a pot of Spanish gold (which, needless to say, may or may not exist). Speaking in the off-kilter intonations of a talking computer, our uncanny guide does its best to connect these dots as it traces a path through a labyrinthine essay on family, fortune, and history. Starting with the Springer family’s obsessive hunt for buried Spanish gold, The Disappointment twists through the etymology of the word “discovery,” investigates an enigmatic stone carving, contemplates the impact of the Korean War on the filmmaker’s father, and studies a text transcribed by his mother under the influence of a Spanish ghost. Singer patterns his ideas with such daunting complexity it’s easy to get lost. But The Disappointment doesn’t—it’s amazing to explore.