This story is a sequel to G5 Adventures in Straight Outta Nowhere: Scooby-Doo! meets Courage the Cowardly Dog
With the second cutie mark crystal down and knowing what they are facing in regards to Misty's biological mother and Opaline's adopted daughter, Paradise Moonray, the ponies buckle down on research on where the third crystal might be, where Sunny finds some very interesting pages in her father's journal about some sort of creatures called the Smurfs. And in the blink of an eye, the ponies are sent to the same village of the Smurfs for another Unity Quest.
The evil wizard Gargamel as sought out the tiny blue creatures for many years, and finally, he succeeds in chasing the little blue people, plus their pony friends, from their village and through a magic portal created by the very rare Blue Moon-- which transports them to Manhattan and into the life of ad executive Patrick Winslow. Only three apples high and lost in the Big Apple, Sunny and her pony friends must help the Smurfs get back to their world before Gargamel tracks them down and uses the Smurfs' essence to seize control of the world.
But the real question is... will our pony pals aid their friends in returning home? Or will all their efforts be for naught?
(S2E4 of G5 Adventures)