Twilight and Spike are sent by Celestia to the ruins of her old castle for research, and unknown to each other, the rest of the ponies find their way there as well. Meanwhile, trap doors, secret passages and a dark presence known only as the Shadow Pony await them.
"Get your muzzle out of those books and make some friends!" That's what Princess Celestia tells Twilight Sparkle. She may be the smartest unicorn in Equestria, but Twilight Sparkle gets an "incomplete" in friendship. There's more to life than learning magic, after all - so she goes to Ponyville on a mission to make friends. There she meets five special ponies who take her on exciting adventures and teach her the most powerful magic of all... the magic of friendship!