Aeschylus, The Oresteia

Aeschylus ( 525-456 B. C.) is one of the greatest poets in history and is the oldest of the three Tragedy Poets (the others are Sophocles and Euripides). The Oresteia is the only Greek trilogy that survived. In the first part - Agamemnon - he tells how the Greek commander is murdered by his wife Clytaimnestra and her lover Aigisthus short after his homecoming. His wife wanted to revenge the death of her daughter Iphigeneia, sacrificed by Agamemnon ten years earlier (at the very beginning of the Trojan war). The second part - The Libation Bearers - Orestes helped by his sister Electra, kills his mother and her lover Aigistus. In the third part - The Eumenides - Orestes is pursued by the three goddesses who seek revenge in their turn, urged by his mother. I like this trilogy mainly because at a given moment you could say that Orestes is only imagening things. I don't want to spoil so I guess you have to read this work to know what I mean.