Yin finds Yang's old book he wrote when he was 4 and she laughs hysterically. Yang gets the book back but Yin and Master Yo continue to make fun of him. In anger he throws the book outside and it lands in the trash can where Coop is. Coop informs The Night Master of the book and he goes inside it and transforms himself into the villain of the book Dr. Scaryface. One of the characters from the book Mr.Fluzzepants goes to ask Yang for help. Yang refuses but he gets dragged into the world and Yin comes along. They arrive at the world and they goes to find Dr. Scaryface. As they go Yin continues to tease Yang but stops after realizing Yang is more powerful in the world. The people are not happy that Yang isn't caring about his imaginary world and remind him about his pony Comet which is melted. Yang breakdown thinking that Comet is gone revealing that he does care only to realize that his horse is fine and that it was a candy statue of comet that melted. Dr. Scaryface sends his scowly hawks after the group but they mange to kidnap Mr. Fluzzlepants. They go to Dr Scaryface lair and The Night Master reveals himself. He begins to erase all of Yang's creations. He threatens to erase Yin and Yang if they don't join him. But Yang knows that this is his world and that whatever he imagines happens. He imagines himself as a big strong superhero and fights the The Night Master. The Night Master sends the scowly Hawks to attack Yang gives Yin the power and she turns them into Yo Hawks to which Yang add flashlights. The Night Master retreats but not before telling Yang that the world won't exist with out his magic. But Yin tells Yang that it will exist in Yang's heart, Yang agrees but he burns the book and put the characters in a new book he creates.
The episode ends showing Yin finding the book 40 years later Yang attempts to get it back but fails. The characters in the book remark about how familiar this seems.
- This episode features the Night Master as the main antagonist
The letter B in the title is backwards