Deus ex machina
For example, in Euripides' play Alcestis, the heroine agrees to give up her own life in order to spare the life of her husband, Admetus. At the end Heracles shows up and seizes Alcestis from Death, restoring her to life and to Admetus. A more frequently cited example is Euripides' Medea in which the deus ex machina is used to describe Medea, who has just killed people and babies, away from her husband Jason to the safety and civilization of Athens.
- "It is obvious that the solutions of plots... should come about as a result of the plot itself, and not from a contrivance, as in the Medea and in the passage about sailing home in the Iliad. A contrivance must be used for matters outside the drama—either previous events which are beyond human knowledge, or later ones that need to be foretold or announced... There should be nothing improbable in the incidents; otherwise, they should be outside the tragedy as, for example, in Sophocles' Oedipus.
There are many examples even in modern movies and novels. For example, in H.G. Wells's War of the Worlds, the aliens attacking Earth are suddenly killed by bacteria. In Disney's Robin Hood, every problem in the movie is suddenly solved when King Richard returns to England in the end of the movie by arresting Prince John and pardoning Robin Hood from all his crimes. The movie Monty Python and the Holy Grail makes fun of this plot device when the heroes barely escape from an animated monster because the animator died from a heart attack before finishing the movie's animation. Since the monster only existed in the animated scenes in the movie, the animator's death caused the monster to completely disappear from the movie.
- Bushnell, Rebecca ed. 2005. A Companion to Tragedy. Malden, MA and Oxford: Blackwell Publishing. ISBN 1405107359.
- Heath, Malcolm, trans. 1996. Poetics. By Aristotle. Penguin: London. ISBN 9780140446364.
- Janko, Richard, trans. 1987. Poetics with Tractatus Coislinianus, Reconstruction of Poetics II and the Fragments of the On Poets. By Aristotle. Cambridge: Hackett. ISBN 0872200337.
- Mastronarde, Donald, 1990. Actors on High: The Skene roof, the Crane and the Gods in Attic Drama. Classical Antiquity, Vol 9, October 1990, pp 247–294. University of California.
- Rehm, Rush, 1992. Greek Tragic Theatre. Routledge, London. ISBN 0415048311.
- Tanner, Michael ed. 2003. The Birth of Tragedy. By Nietzsche, Friedrich. Penguin: London. ISBN 9780140433395.
- Taplin, Oliver, 1978. Greek Tragedy in Action. Methuen, London. ISBN 0416717004.
- Walton, J Michael, trans. 2000. Euripides: Medea. Methuen, London. ISBN 0413752801.