“The Resurrection was the greatest ‘eucatastrophe’ possible in the greatest Fairy Story–and produces that essential emotion: Christian joy which produces tears because it is qualitatively so like sorrow, because it comes from those places where Joy and Sorrow are at one, reconciled, as selfishness and altruism are lost in Love.” -- J.R.R. Tolkien (The Letters of J. R. R. Tolkien, 1981)
A eucatastrophe is a sudden turn of events in a story which ensures that the protagonist
does not meet some terrible, impending, and very plausible and probable doom.
