It's Spring Break and the Mane 7 are about to board the most glorious yacht ever for a relaxing cruise. But Rainbow Dash is convinced that Equestrian Magic is on the loose and won't let anyone rest until she finds it. This leads to disaster on the high seas, a trip to Ponyville, and the ultimate discovery that Equestrian Magic related to the Storm King has seeped into their world and is threatening everyone on board the yacht.