One of my favourite novels of 2017 was the historic fiction debut A Mighty Dawn by Theodore Brun. The paperback edition has just been released, and the author has very kindly agreed to provide a guest post exploring one of the novel’s central themes. The Ragnarök as an idea has made something of a comeback in popular culture in recent years. Marvel comic books, blockbuster Hollywood movies, Viking TV shows and of course plenty of Viking novels have all used it to great effect. Like the idea of Armageddon – or indeed any foretelling of the end of the world – it has a powerful grip on the imagination. And if it’s got Tom Hiddleston anywhere near it, you know it’s hit the mainstream. In fact, Ragnarök was a concept central to the early Viking mind. They believed that fate was unfolding inexorably towards this cataclysmic event, when the whole cosmos would be torn by chaos and conflict, and fall into eventual destruction – the so-called “doom of the gods”. Our knowledge about these Old Norse beliefs comes from two sources. The Völuspá or Vala’s Prophecy, the oldest known poem in Scandinavian literature, parts of which date from the 6th century;...