Rainbow Dash, Lloyd Garmadon, and Squidward Tentacles are just a trio of citizens of a town called Midava. But one day, Rainbow gets sick of the same routine that she and her friends do every single day. So the trio go on a voyage on the Midnight Princess that was owned by the legendary Captain Twilight Sparkle. But the trio needs to face other things while on the voyage. An apple fritter-crazy unicorn, twins that seek adventure, a judging rabbit, and another ship crew with a ghost taking charge.