What name does Tolkien give to the catastrophic but hopeful turn in a fairy-story?

J.R.R. Tolkien called the catastrophic but hopeful turn in a fairy-story a eucatastrophe.

He introduced the term in his 1939 lecture and later essay “On Fairy-Stories.” It combines the Greek prefix eu-, meaning “good,” with catastrophe, referring to a sudden reversal in events. Tolkien used it for a joyous turn that brings deliverance after apparent disaster.

Eucatastrophe does not mean that a story has no sorrow or danger. Instead, it describes a sudden glimpse of joy and hope that does not erase the reality of suffering. Tolkien considered this effect central to the power of fairy-stories and connected it with his Christian understanding of hope.

Readers often use the term simply to mean any happy ending, but Tolkien’s idea is more specific. The reversal must arrive unexpectedly, emerge from the story’s crisis, and create a feeling of wonder. The Eagles’ arrival at the Battle of the Black Gate is a well-known example from The Lord of the Rings.