Twilight Sparkle, Rainbow Dash, and Pinkie Pie travel to Las Pegas for a bachelorette party to celebrate their friend Rarity's impending marriage. However, after awakening from a long night of partying, Twilight, Rainbow, and Pinkie find they have no memory of the night before and must race against time and across Equestria's infamous city of sin to find Rarity so the wedding can occur.