Rumble has been in a loving relationship with the filly of his dreams for a whole year and has really made close friends with the rest of the Crusaders, along with his already best friend Dinky and new second best friend Tender Taps. But now they have other things to figure out, like why Twilight is planning a festival, why she seems to enamored with Tender Taps, why she placed Rumble in charge of Flurry Heart, and why Changelings and Sirens are suddenly invading.

The last part may not be so ideal for them, now they must team with The Elements and many other ponies to stop the invasion of the returning Queen Chrysalis and her Dazzling allies.