Raw and dramatic, the tango is supposed to be a conduit for grief—not, as the dance occasionally is in Frédéric Fonteyne’s dramedy Tango Libre, a source of it. But the tango is also a cause of humor, a device that leavens the tensions of a romantic triangle that grows more complicated when reserved prison guard Jean-Christophe (François Damiens) becomes intrigued by his new dance partner Alice (co-scripter Anne Paulicevich)—who appears to have close relationships with two of Jean-Christophe’s inmates, and a son who belongs to one of them. At first, Alice’s tango lessons threaten to cleave her unconventional family apart; instead, her husband Fernand (Sergi López) asks an Argentine prisoner to teach him to dance—leading to a disarmingly silly male-male dance sequence that flirts with the madcap but feels emotionally true. Eventually the plot becomes its own dance of large, unrestrained emotions, as the characters’ lives outside and within the prison’s walls dart and weave and eventually contract. To truly tango, we figure out by the end, it takes more like four or five.