After the painter, Cavaradossi, discovers his fellow revolutionary, Mario, hiding in the church of Sant''Andrea della Valle, he agrees to help hide the escaped prisoner. Meanwhile, the police chief, Scarpia, has aroused the suspicions of Cavarodossi's girlfriend, Tosca, that his recent secretiveness is a result of an affair with another women. While Tosca searches for her supposedly unfaithful boyfriend, the police follow her and arrest Cavarodossi. Eventually, in order to prevent Cavarodossi's execution, she agrees to have sex with Scarpia. Nevertheless, Cavarodossi is still killed, and Tosca commits suicide.