The difficulty inherent in the exclusive use of exterior scenes appears very strikingly in Euripides’ _Cyclops_. Here the action would naturally take place in Polyphemus’ cave, as it does in Homer’s _Odyssey_; but, theatrical conditions making that impossible, the scene is laid before the cave’s mouth. Contrary to verisimilitude, therefore, the poet is obliged to allow Odysseus to pass in and out without let or hindrance. Why, then, does he make no attempt to escape? Euripides anticipated this query and explained Odysseus’ remaining by regard for his companions’ safety (vss. 479 ff.). But why was it not equally feasible for his comrades to leave the cave and for all to be saved together? The poet can think of no better motive than that Odysseus’ pride and sense of honor caused him to desire to take vengeance on Polyphemus for having murdered some of his followers (vss. 694 f.). Being unable actually to represent an interior scene the Greek playwrights gladly availed themselves of several substitutes. The most common of these was the messenger’s speech (see p. 164, above), by which occurrences that had taken place indoors were related to the chorus or to actors before the house. Another substitute was found in the cries of characters murdered behind the scenes (see pp. 128 and 229, above). A third method consisted in throwing open the doors in the background and revealing a scene of murder done within (see p. 128, above). We are told further that sometimes, when the doors were flung open, a platform, with a tableau mounted upon it, was pushed forward for a few moments (see the discussion of the _eccylema_ on pp. 284-89, below). A fourth evasion of the restriction occurs in Euripides’ _Hippolytus_, vss. 565 ff. Phaedra from her couch in the proscenium colonnade hears the voices of her confidential slave and Hippolytus engaged in conversation within doors. She invites the chorus in the orchestra near by to join her in listening at the door—a proposal which for obvious dramatic reasons the choreutae cannot accept; but her own cries and exclamations of despair as she listens stir the audience much more profoundly than the conversation itself could have done. Thus the main portion of the dialogue between Hippolytus and the slave is supposed to take place indoors. It is concluded before the house, the two interlocutors entering the stage at vs. 600.