A month after returning home from her adventures with the Saphire Stone, and Daring Do's already dying to head back into the field. Unfortunately for her, absolutely nothing seems to be happening. No danger, no disaster, no adventure ANYWHERE. Until she receives a letter in the mail, telling her to meet a mysterious pony at the Canterlot Museum. Upon arrival, she finds that the pony is not so mysterious after all -- in fact, she's just the opposite. Cassablanca Lily, of the Canterlot Lilys, is one of the most well known ponies in all Equestria. However, what she shows Daring is not. Somewhere below the Canterlot Museum lies a secret vault, lost to the civilised world for nearly two hundred years. The treasures it holds are innumerable and invaluable, but it's not what's in there that matters; it's what isn't. The Gryphon's Goblet, a powerful chalice immortalised in fairy tails, is missing, and no one knows for how long. It could be one year or one hundred and fifty. But one thing is certain: someone has to get it back, before whoever stole it finds out how to harness it's powers. And who better to do so than the amazing adventurer Daring Do?