For 500 years, the secret society of the Midnight Sun has been waiting for the homunculus, the man-made man, to rise, and now Dr. L and Ms. Mauvais are going to throw Cass and Max-Ernest to the sharks unless they tell them where he resides.

After finding out their teacher was actually Owen, the accent changing member of the Terces Society, they are introduced to the great magician himself, Pietro, who gives them a mission.

This time teaming up with a new classmate named Yoji (who prefers to be called Yo-Yoji), the three need to escape the grasp of their parents, and find the alchemist's grave.

The Midnight Sun took there because Lord Pharaoh's, the nasty man who created Mr. Cabbage Face, the homunculus, grave is there, and with it, all of his alchemist things, which is what Ms. Mauvais and Dr. L want in order to help their mission in receiving immortality.

Their plan is to create a sonic boom with it, and make the mountain avalanche onto the Midnight Sun and seal the coffin in the ground.