La Luna is a 1979 Italian drama directed by Bernardo Bertolucci in which Caterina, a famous American opera singer, loses her husband and travels to Rome with her troubled 15-year-old son Joe, who quickly spirals into heroin addiction — and in a desperate, boundary-destroying attempt to pull him away from the drugs, Caterina crosses into an incestuous relationship with him, sexually stimulating him during his worst withdrawal moments, sending both mother and son deeper into a dysfunctional emotional vortex that only begins to unravel when Caterina takes Joe on a quest to find his real biological father.