When eleven-year-old CODY feels left out and alone [abandoned] by his too-busy divorced parents and his off-at-summer-camp friends, he ventures into the woods for the first time. There he meets two kids who claim to live in a city deep below the surface of the earth where everyone has amazing paranormal abilities. Of course, Cody doesn’t believe them. [Of course. But later when no one believes Cody about seeing a man-sized rat, he won't understand how they can be so dense.]
The next day, Cody’s mom bails on him when she starts dating a new guy, and Cody’s dad says he’s moving to across the country with his giggly girlfriend. Cody has had enough and storms off to the woods. This time, he begs the kids to take him to their underground city. Even though [when] they warn him [that] once he goes down, he can never go home again, Cody is all-in. [He can never go home because it's against the rules or because it's physically impossible?]
With strange caves to explore and plenty of new friends with crazy abilities, Cody thinks he’s scored the perfect new home. Except outsiders from the surface are not allowed. [So the kids who brought him down and the plenty of new friends he's made are unaware that surfacians aren't allowed?] But when Cody is discovered by the Council of Elders, instead of executing him, they ask for his help. [If execution is the usual penalty for being there, you'd think that would have been mentioned by the kids who brought him down.] With his knowledge of the surface, he may be able to find out what happened to their missing Detectors, the citizens who protect the underground city by patrolling the surface.
As a way to find the Detectors, the council wants to teach Cody paranormal abilities and create a psychic link between Cody and the Detectors. [Have they tried creating a psychic link between the two kids Cody met in the woods and the Detectors?] Cody is determined to help his new home [friends]. The problem is, he’s failing his simplest paranormal classes, and a man-sized rat, RATMAN, attacks [him] every step of the way by using paranormal abilities to create Cody’s dangerous “accidents.”
Since Cody is the only one who sees the giant rat, no one [else] believes Ratman exists. So while Cody struggle[s] to find the Detectors, he wants to figure out who or what Ratman is and why he’s attacking him.
When Cody finally develops visions in his meditation class, he gets glimpses into the mind of Ratman. He discovers [that Ratman is usually thinking about cheese.] there’s a real man behind the rat illusion, [If you're gonna create the illusion that you're an animal, you oughta be able to come up with something better than a rat.] and that man is a vengeful council member, KIRK, who has been using the missing Detectors to locate a mysterious power source that can create an earthquake. Cody fears Kirk is about to get his revenge for the death of his family by destroying the city with a man-made earthquake. [This is the plot of that Star Trek episode where Kirk destroys the planet Romulus as revenge for some Romulan woman digging Spock more than she digs Kirk.] [Also, how did this Elder's family die? Unless everyone in the city was responsible, destroying the city seems like overkill.]
But when the entire Council of Elders is the next to disappear, it’s up to Cody and his friends to stop Kirk. [I see we've decided to call him Kirk instead of Ratman. If Ratman is an illusion and is actually Captain Kirk in a rat costume, maybe the title should be Kirk's Revenge. You'd see huge sales to Trekkies who think it's fanfic.] Despite their best efforts, one of Cody’s friends is killed [The one in the red uniform shirt.] and the remaining friends are held under Kirk’s hypnotic spell.
As the earth begins to shake, Cody is left to face Kirk’s wrath [The Wrath of Kirk] alone and save his new home. Cody draws on the simple talents he had on the surface—quick thinking and telling a convincing lie—to deceive Kirk and refocus the power source to kill him. [Quick thinking and lying may be useful talents, but do they allow you to refocus a power source that's causing an earthquake so that it kills one wererat?] The council and the Detectors are then freed from Kirk’s control.
If these other kids are able to come to the surface, why wouldn't Cody be able to come back and go home?
Are the people who were unable to see Ratman able to see Kirk?
Hard to believe they pin all their hopes on an eleven-year-old stranger who fails even the simplest paranormal classes, just because he has some familiarity with the planet's surface. It would be easier to have Cody teach someone who aced his paranormal classes about the surface.