Nightingale, image of Eucatastrophe

“[Luthien] Tinúviel’s attendant bird, the nightingale, is a fitting emblem of eucatastrophe, pouring out its fluting song when all is dark. Its symbolic significance may be measured in the words of men on the Western Front. [Tolkien’s friend and fellow TCBS member] Rob Gilson, hearing a nightingale in the early hours one May morning from his trench dugout, thought it ‘wonderful that shells and bullets shouldn’t have banished them, when they are always so shy of everything human’, while Siegfried Sassoon wrote that ‘the perfect performance of a nightingale… seemed miraculous after the desolation of the trenches’.” (Garth, Tolkien and the Great War, 265)