Set entirely in Wuhan, China during the 76-day COVID lockdown in early 2020, “76 Days” is a tight, tense, and, at times, unrelentingly emotional account of front-line pandemic medical combat. As a piece of high-impact experiential movie journalism, it feels close to the style of a standalone “Frontline” episode, missing only Will Lyman’s low and drama-heightening narration. As an account of what the pandemic was like at our current pandemic’s Ground Zero, it feels like essential viewing for now and the future.