Frost attempts to find out what happened to Princess Sunset Shimmer. Upon investigation the Princesses old castle Frost discovers a diary left by someone named Twilight Sparkle who according to the diary was a Princess as well even before Sunset. As well as Two other princess she never heard of princess Celestia and Luna who were the original owners of the castle. As she begins to look through the diary she begins to wonder what happened to Twilight, Celestia and Luna . And why and how Sunset became the Princess in the first place, Watching from the shadows is Discord how Is Discord connected and just why does he think frost would be the best chance to find twilight?