Lin Yuan, a special operations team member who once served in the field army, makes a mistake during a special operation, resulting in the death of all his teammates and hostages. Hiding away with the haunting memories, he accidentally gets involved in the criminal group from his past, thus stripping away the inner depths of the criminal group and their actual world layer by layer…

The film tells that Yan Xian's master passed him a demon catcher before he died, but the demon catcher was stolen by the three cat demon. The stranger caught the "demon in the ear" inside the king. Yan Seventeen caught a rat demon who had stolen his money and treasure, and this rat demon named Rat Laibao was the real successor of the demon catcher.