In Rome, June 1800, the former consul Angelotti escapes from Castel Sant'Angelo and takes refuge in the church of Sant'Andrea della Valle. He's aided by the artist Mario Cavaradossi, who supports the revolutionary cause and loves the singer Floria Tosca But the diabolical Baron Scarpia is on their tail, aiming to capture Angelotti and make Tosca his own. In her desperate attempt to save her beloved, Tosca makes a fateful decision.