The play opens with a watchman standing on the roof of the palace of Agamemnon at Argos. He explains that Clytaemestra has ordered him to keep a lookout each night for the light from a series of beacon fires that will signal the long-awaited fall of Troy. He has carried out this duty faithfully for several years already and is getting demoralized. Suddenly he observes a beacon burning in the distance and realizes that the war is over. The watchman is excited for a moment by the happy thought that his long vigil is ended and that his king will finally return home, but then a feeling of gloom comes over him. He refuses to state aloud the cause of his foreboding but remarks that the walls of the palace could tell the story if they were able to speak. The watchman determines to remain silent. He will be satisfied to welcome his beloved king home again. He goes out to tell the news to Clytaemestra.
The watchman's speech sets the gloomy, tense mood that will be maintained throughout the play. There is skillful artistry evident in this powerful opening and full use is made of dramatic irony. Moreover, the watchman has been made into a real man instead of a mechanical giver of information. His ambiguous reaction and brooding thoughts are genuine in the circumstances. They immediately arouse the interest of the audience and give added poignancy to his guarded comments.