During a deadly Chicago heat wave that's claiming hundreds of lives, Robert, who's stuck in his apartment alone, fears he's going to be the next victim. In the apartment above him lives a shell-shocked Vietnam veteran who talks obsessively about the corpses of his war experience while alternately listening to Die Meistersinger and Madama Butterfly. One day, Robert ventures forth into the searing heat to gas up his car. Immediately he encounters enigmatic Lucy who is trying to escape her brutal fiancé, Matthew Gliss. On a whim, Lucy invites Robert to her apartment where she shows him her mysterious tattoo and tells him of her dangerous life with Matthew Gliss. She warns Robert that if Matthew ever catches them together he should run, not walk, because Matthew won't think twice of killing him. So begins the risky, short-lived relationship that leads to a chilling climax. Each of Robert's increasingly hallucinatory recollections of what happened during the heat wave leads him to profoundly question his own culpability.