As a princess, Twilight has her ups and downs when it comes to approaching her new found responsibilities. That all changes though when she summoned back to Canterlot to help Princess Celestia and Luna with an important task. Though she has no idea what the task is, she is eager to prove herself. Eventually she is given the task of discovering a powerful magic hidden deep within the caves below Canterlot. To her surprise though, Celestia and Luna have also called upon three powerful wizards to help discover this new force. At first they all seem friendly, and willing to help Twilight with her task. Soon though it becomes clear that somepony is out to sabotage their hunt, and use this new magic for their own personal gain. Now not only does Twilight have to complete her task, but she has to figure out which pony is the traitor in their mist.