Crisis and Peripeteia

Crisis noun - A time or state of affairs requiring prompt or decisive action.

Peripeteia and crisis are semantically related In some cases you can use "Peripeteia" instead a noun "Crisis".

Peripeteia noun - A sudden and unexpected change of fortune or reverse of circumstances (especially in a literary work).

Crisis and peripeteia are semantically related in critical juncture topic. Sometimes you can use "Crisis" instead a noun "Peripeteia".