In On Fairy Stories J.R.R. Tolkien states that eucatastrophe “does not deny the existence of dyscatastrophe, of sorrow and failure; the possibility of these are necessary” (OFS 153). Eucatastrophe, the “sudden joyous turn”(OFS 153) in a good fairy story is not only made possible by dyscatastrophe, but relies upon it. By turning away from sorrow and despair, the turn towards joy is made all the more great; the moment becomes more than just a happy ending and becomes eucatastrophe. In The Silmarillion Beren and Lúthien face seeming failure and doom many times but there is always an extraordinary turn towards eucatastrophe.
Many of the dyscatastrophes that Beren face come as a result of being separated from Lúthien. Thus the sudden turn to eucatastrophe always occurs when Beren and Lúthien are reunited. For example, although Beren is physically tormented and worn from his first journey to Doriath, it is only after Lúthien inexplicably “vanishe[s] from his eyes” (165) where he first experiences dyscatastrophe: