An American naval vessel enters a whirlpool and is transported to Equestria, it's crew having been turned into ponies. With no way to get back, the new ponies ally themselves with Twilight Sparkle and her friends to find a powerful magic artifact for Princess Celestia. However, something may have followed them through the whirlpool...
Takes place after "Sisterhooves Social" but before "Cutie Pox"