Angry passion and visual energy define this extraordinary muckraking documentary. The anger and rage that ignite it stem from the puzzling illness that overtakes Lori Hall-Steele, sister of Timothy Grey, who co-directed the film with Breanne Russell. At first, the diagnosis would seem to be chronic fatigue, but the symptoms (muscle failure, paralysis) begin to wildly contradict each other, alternately suggesting Lupus, Lou Gehrig’s, and Lyme disease. Hall-Steele’s doctors mask their cluelessness in smug tones; one even tells her, “Everybody dies.” More infuriating are the indifference and outright hostility of the Michigan Department of Environmental Quality when Grey discovers a freakish outbreak of identical illness in the area, one that aligns with the high degree of toxins in the local well water. This would be powerful, galling stuff in itself, but instead of limiting Under the Eightball to one woman’s plight, Grey and Russell confront the history of Lyme disease and its origins in the U.S. government’s medical experiments (using captured Nazi and Japanese scientists) to develop biological warfare. These experiments were practiced on all of us, Grey and Russell assert, and they make a persuasive case. Grey and his sister were born and raised in Flint, Michigan, which makes it tempting to reference Flint’s other native documentarian, Michael Moore, with whom they share a crusading ferocity. Such comparisons burn away fast, however: The heartbreak that informs the universal reach of Under the Eightball is uniquely personal.