The boys hang around the carnival all day, going on rides and playing games, but at sunset, Jim vanishes. Will finds him in the Mirror Maze and pulls him out. Jim, silently mesmerized by what he saw, wants to go back later that night. Will reluctantly agrees to accompany him. As they're walking back home, they trip over the lightning rod salesman's leather bag. There are still a few lightning rods within. Will wants to head home to dinner, but Jim convinces him to stay and follow this mystery, so they walk back to through the carnival.
The boys approach the chained-off carousel with an "out of order" sign. Jim jumps the chain and Will follows, but as Jim gets on the carousel a large man with bright red hair, blue eyes, and rippling biceps lifts him up in the air. Will runs to help, but the man lifts him up as well. "Put them down," says a gentle voice. This second man is tall, with a pale, pockmarked face and black hair. He is wearing a black suit with a blood-red vest. This second man is Mr. Dark; the first, Mr. Cooger.
Mr. Dark hand Jim a calling card. It changes colors from white to blue to red to green. Names magically appear on the card. Jim looks at it calmly. Mr. Dark rolls up his sleeves to reveal an arm covered in tattoos of eels, worms, and Latin scrolls. He is the Illustrated Man as advertised on the poster. His tattoos dance on his arms. Jim and Will give Mr. Dark false names, which he realizes. Then Mr. Dark stops his tattoo show and tells the boys to run home for supper.
The boys run away, but Jim climbs a tree when the two men aren't looking and Will follows. The carousel begins to move backwards and Mr. Cooger leaps on. Each time he goes around, he appears to get younger. He stays until he has changed to a boy of twelve and then leaves with Mr. Dark. The boys, embroiled in the mystery, follow him to Miss Foley's street. Mr. Coogar enters under the guise of her nephew and Jim walks up to the house to ring the bell. The plan is to make sure that the boy in the house is really Mr. Cooger and then call Miss Foley afterwards to warn her. Will is terrified, but Jim isn't scared at all.
Jim rings the bell and Miss Foley answers and lets them in. Miss Foley laughs at their fears; the earlier events at the carnival have not had a lasting effect on her. She wants to introduce them to her nephew, Robert, who had been missing earlier at the carnival. Before she does, Will says that he has something terrible to tell her, and Jim elbows him hard to shut him up. To cover up his blunder, Will recalls the sign on the barbershop: "Closed on account of illness," and says that Mr. Crosetti is dead, though whether this is true or not is unclear.
Robert appears, and the boys satisfy themselves that it is the disguised Mr. Cooger. They refuse Miss Foley's offer of dinner, but Robert suggests that they join him and Miss Foley for dessert afterwards at the carnival. Will is alarmed, afraid for Miss Foley's safety. Jim agrees to meet, but Will intercedes and says they both need to stay home that night. Robert then asks them to meet him tomorrow by the sideshow. Jim agrees. On their way out, Will recalls the tune that the carousel played as it spun backwards: Chopin's "Funeral March."
The boys return home at 7:00, and their parents send them to bed without dinner for being late. Unable to warn Miss Foley, they obey. At 10:00 Charles comes to Will's door and warns him to be careful before heading out to the library. Will wants to shout to his dad that the night is not safe, but he does not. Will tosses marbles at Jim's window, but, uncharacteristically, Jim does not respond.
Jim appears to be changing, bit by bit, exhibiting chinks in the armor of his fearless, unfazed character. His encounter with the carnival has introduced both fear and wonder into his life. This is illustrated, among other things, by his obsession with "mysteries": Jim once thought that he knew everything, but his obsession with mysteries tacitly acknowledges the unknown. Unfortunately, he responds this encounter with the unknown by acting carelessly and rashly, driven to get to the bottom of the mysteries of the carnival and dragging Will with him.
What's more, Jim doesn't seem concerned at all for Miss Foley. His only concern is for knowledge. "Jim, you don't give a darn about Miss Foley," Will shouts at one point in the chapter. Will knows Jim well enough to know that nothing will stop him from finding what he wants. Indeed, Will is struck by the same feeling that used to have for an old dog he used to own. This dog would be fine for many months, until all of a sudden it would run away and not come back for days. When it finally did return, it would limp, scraggly and smelling of swamps and dumps. The dog would stay for another few months, and then the cycle would repeat itself.
These chapters also make it clear that the carnival is inextricably associated with age. The Mirror Maze showed that it could make people appear younger, but this episode with the carousel indicates that Dark and Cooger have the power to actually turn back the aging process. Of course, this chapter also begs the question of what happens when the carousel runs forward. The "Funeral March" is a symbolic choice of music for the carousel. As the carousel spins backwards and the music plays in reverse, it is as if Mr. Cooger was marching away from the grave, instead of towards it.
In Chapter 20, Charles continues to display his dejection and depression over his old age. He feels that he cannot connect with his son in any way. There is nothing to say and nothing they can do together. As he leaves Will's door, he even says, "sometimes I almost wish we'd never..." before either trailing off or walking out of earshot. These are strong words, and it is unlikely that he would ever truly wish he had never had a son. There is distance between them, but it seems clear that he loves his son. It is more likely that these wishes are more the result of the fact that looking at his son only makes him feel older, and he is wallowing in what can rightly be termed a pretty serious midlife crisis or depression. This distance is also felt by Will. As his father approaches the door of his bedroom, Will knows that he will not actually enter. He will "walk around, talk around, back off from a thing, yes. But come sit, listen? When had he, when would he ever?"