peripeteia

A sudden reversal of fortune as a plot point in Classical tragedy.

Any sudden change in circumstances; a crisis.

Once more I was a man in a myth, incapable of understanding it, but somehow aware that understanding it meant it must continue, however sinister its peripeteia.

They were to bestride the Algerian scene like demigods until the tragic peripeteia of 1961 […]

A turning point in psychosocial development.

The visual moment whose consequences Freud began to ponder in the essay on the phallic stage has evolved into a peripeteia: "Some day or other it happens that the child whose own penis is such a proud possession obtains a sight of the genital parts of a little girl; he must then become convinced of the absence of a penis in a creature so like himeself. With this, however, the loss of his own penis becomes imaginable, and the threat of castration achieves its delayed effect."