A gaoler enters and looks over the parapet to see if the soldiers to whom is entrusted the grim task of execution have arrived. Led by a sergeant, the picket enters, bringing Cavaradossi. The gaoler, after making him sign a paper, tells him that he has an hour, and that a priest is at his disposal. Cavaradossi, after giving a ring to the gaoler as the price of the favour, is allowed to write a letter, and sings his beautiful air, one of the chief lyrical gems of the opera, "E luce van stelle." It ends emotionally, and the singer bursts into tears with the thought that never was life so dear to him as now when he is within sight of death. Spoletta comes in bringing Tosca, and is amazed to find that she brings a safe-conduct. Tosca and Cavaradossi join in a finely expressive duet, in which the latter learns of her devotion, and how for him she killed Scarpia. Towards the close the voices are unsupported, and the whole number has a very characteristic force and movement. [Illustration: PUCCINI AT TORRE DEL LAGO IN HIS MOTOR BOAT "BUTTERFLY"] The sky has gradually been getting lighter, and the passage of time is marked by the striking of the hour of four by the church clock. Then Tosca gives the final instructions to the condemned man. "As soon as they fire, fall down." Cavaradossi, in his joy at his coming release, is even able to be humorous, and suggests that he will be acting like Tosca. Tosca watches the supposed execution from the parapet. "How well he acts!" she cries, after she has covered her ears with her hands to shut out the sound of the shooting, and then sees her lover prostrate on the ground. Leaning over, she calls to him: "Get up, Mario, now. Quickly away, Mario, Mario." Then with a heart-piercing cry she learns that Scarpia has been false to the end, and that the execution has in very truth taken place. By this time the news of Scarpia's death has come out, and Spoletta naturally fixes on Tosca as the murderess. The soldiers' voices are heard joining in the hue and cry, and Sciarrone comes in to seize Tosca. Tosca after thrusting back Spoletta nearly to the ground, hurls herself from the parapet. Her last thoughts are of the tyrant who has so cruelly wronged her, and her last words are: "O Scarpia, we shall face God together!"