Rich in information, fiercely timely and as dense as it is accessible, Lee Anne Schmitt’s third feature is a biography of John Brown (1800–1859), albeit one that uses the life of the famed American abolitionist as a jumping off point to narrate myriad other stories of Black discrimination and resistance that chime with his legacy. As Schmitt criss-crosses the country visiting sites of protest and remembrance marked and unmarked and referencing Frederick Douglass, Sun Ra and Nat Turner, her own feelings are always present. For, as she states at the outset, “Purge This Land” was made for her son with partner Jeff Parker, whose enveloping soundtrack channels 1960s Black heritage in tying together the film’s thrillingly heterogenous elements.