Legends often have a way of coming true. Twilight Sparkle knows this all too well, having seen first hoof several of them come to life before her very eyes. So when she receives a recently published book on dragon mythology, she jumps at the chance to learn about their history.

Unfortunately she gets the book on the same day that Twilight promised Rainbow Dash that she would help her train for the Wonderbolt tryouts next week. To make matters worse, Shining Armor drops in unexpectedly to pay his little sis a visit following the honeymoon. Could juggling the responsibilities to her friend and her brother possibly get any trickier for Twilight?

Of course it can. And when it does, it will lead Twilight Sparkle, Shining Armor, and Rainbow Dash into the very heart of the Kingdom of Draconia to unravel one of the greatest mysteries of old. What happened to the dragon Iris?