Asta and Yuno spend six months training for the upcoming Magic Knights Entrance Exam. Everyone seems to think Yuno is sure to pass, but worries that Asta is just wasting his time.

The dungeon itself turns against the Magic Knights as they fight to escape—and to keep a badly wounded Asta alive. Mars remembers how he came to be.

As the situation in the Heart Kingdom deteriorates beyond belief, Captain Yami Sukehiro pushes past his limits.