Anagnorisis ( /ˌænəɡˈnɒrɨsɨs/; Ancient Greek: ἀναγνώρισις) is a moment in a play or other work when a character makes a critical discovery. Anagnorisis originally meant recognition in its Greek context, not only of a person but also of what that person stood for. It was the hero's sudden awareness of a real situation, the realisation of things as they stood, and finally, the hero's insight into a relationship with an often antagonistic character in Aristotelian tragedy.
-- Wiki

Peripeteia /ˌpɛrəpɨˈtaɪ.ə/ (Greek: Περιπέτεια) is a reversal of circumstances, or turning point. The term is primarily used with reference to works of literature. The English form of peripeteia is peripety. Peripety is a sudden reversal dependent on intellect and logic. In modern Greek, περιπέτεια means adventure. 
-- Wiki