The Alicorn Amulet has been safely locked up in Castle Canterlot but when it goes missing three worlds will be placed in peril. Heroes from all worlds must together or succumb to the darkness that threatens peace and harmony.

For awhile now, Princess Luna has guided and kept safe the Cutie Mark Crusaders. Now at long last they have achieved their goal. She throws a party to celebrate the occasion and opens up the doors of friendship to another