It was supposed to be a simple vacation. Just a chance to get away from the daily grind, explore a new city, and catch up with an absent friend. But when that friend happens to be Harry Dresden, all bets are off.
A magical ritual has begun in Equestria, and it's not in any of Twilight's books. It's no spell a pony ever cast. It's dangerous, destructive, and there's no getting out of it. It's name is the Holy Grail War.