Viper1011
When Dream is about to be taken to the prison, Tommy is telling dream to drop things of his thing into the hole, which dream does. For tommy that wasn't enough, he then orders dream to drop his mask in there as well. Dream refuses.
When Dream refuses Tommy gets the mask of reviling dreams face. Dream drops to the ground covering his face refusing to move. It doesn't take long for the monster to take control. The monster escapes.
Since not surfacing since dream was a child the monster tries to find it's way back to places it remembers, so as the monster travels reviling dreams past, the others try to track down dream, along the way they learn that there is more to Dream that meats the eye.