TL;DR

Oswald is a school-kid who lives in a town with his poor family due to the mill closing and over the summer he spends his days alone in the library and at Jeff’s Pizza. When Oswald enters a closed-off ball-pit, he goes back in time to Freddy’s in the year 1985. He makes some new friends there but one day enters to find a Spring Bonnie has killed six kids. When Oswald comes back to the present, Spring Bonnie follows but everyone else sees him as his Dad. His Dad’s body was in the ball-pit and Oswald successfully fights off the Spring Bonnie until he wakes up.

Full Summary

A ten year-old student named Oswald lives in a town with his parents, but life used to be so much better. Three years ago, the mill that the town was built around had closed down, which caused many people to lose their jobs. One of these people was Oswald's father which was devastating for the family. Oswald's mother is a doctor and provides most of the household income, but her long work hours means Oswald doesn't see her very much. He spends a lot more time with his cat, Jinx and his father who now works at a convenience store named Snack Space. The mill's closure also affected Oswald's best friend, Ben, whose family moved away. Oswald doesn't have any other friends at school, so he fears that the summer break will be lonely and boring without Ben's company.

On the last day of school, the students were allowed to bring in an electric device, but Oswald didn't have any devices to bring in, so instead he decided to draw. Recently he had found himself drawing mechanical bears, bunnies and birds, but he was unsure why. They were life-sized and had metal skeletons inside, and he couldn't decide whether he found them creepy or cute. He compares them to a Japanese horror film he likes to watch named Zendrelix vs Mechazendrelix where the video effects looked very unrealistic.

Every day of Summer, Oswald's father would drop him off at the library where he could spend a few hours reading and using the computer. He would then go to a small pizzeria named Jeff's Pizza for a cheese slice and an orange soda. The building was a little unsettling to Oswald - it was a large empty space with an unused stage, a blocked off ball-pit and strange faded murals across the walls. Additionally, Jeff was a little creepy, with bloodshot eyes he looked like a zombie and he was the only worker in the building. At the end of the day, Oswald would talk to Ben over text and get jealous over his holiday plans for the summer at Myrtle Beach. Ben asked what he was doing, and felt sorry for him when he heard it was the same thing every day. After the conversation with Ben, Oswald started to get angry about the repetitive days.

On the way to the library the next day, Oswald lashed out at his father and slammed the car door in rage. He decided in retaliation to hide from him when it was time to pick him up from Jeff's Pizza, so he decided to take off his shoes and enter the ball-pit. The plastic balls were covered in dust and a sticky substance, but quickly Oswald sank under until he started struggling to breathe. When he arose from underneath, he found himself in a ball-pit in a 1985 Freddy Fazbear's Pizza arcade. He looked around the bright room to see the animatronic characters he had been drawing recently, and made friends with two kids of his age named Chip and Mike. They all play arcade games together until Oswald gets worried about his father looking for him in his world. He sinks back into the ball-pit, counts and then comes back out in Jeff's Pizza at the exact same time he had entered. After finding Freddy's, Oswald's mood is boosted and he goes back there daily for a few weeks. One day, he feels guilty for using all of Chip and Mike's game tokens, when suddenly his pockets fill with tokens of his own. Also, at Freddy's he seems to see a still creepy Spring Bonnie watching from the corner of the room, but he ignores it and keeps playing.

As a result of his excitement but confusion for discovering Freddy's in the ball-pit, Oswald asks his father if he remembers Freddy's from when he was a kid. He responds with a yes, but his voice becomes trembly. Once again, Oswald enters the pit only this time he hears screaming and the whole room in a panic. In the corner of the room, he sees Spring Bonnie again who lures him into a party room backstage. There, he sees six dead children sat up against the wall with party hats on their heads. Oswald looks at Spring Bonnie knowing that he was the one who had done it, and away ran as fast as he could before the bunny could grab him.

When he came back through the pit, he emerged to see his father angry at him for hiding from him for so long. In the previous, no time had passed in the present day, but time it had. When Oswald's father approached the ball-pit to take Oswald away, Spring Bonnie pulled his father underneath. The bunny emerges from the pit and takes Oswald to his dad's car. He locks him inside, but while Oswald fears he is about to kill him, Spring Bonnie simply drives to his home and takes him inside in complete silence. Oswald runs to his room to call his mom at work, and she comes home for the emergency to tell Oswald that his father is in bed. Both Oswald and his cat, Jinx, see Spring Bonnie while everybody else appears to see his dad.

A few days later, on the first day of the new school term, Oswald meets a girl on a bench named Gabrielle. She tells him how she's new in the town and talks to him about her fascination with Greek mythology. Her words seem to inspire him, and give him the courage to go back and beat his demons. Oswald forms a plan to go back to Jeff's Pizza in the hope that his father is still in the pit, and tries to sneak out of the house without the bunny hearing him. When he gets to the pit he finds his dad's body inside of it, completely unconscious. When he tries to pull him out, Spring Bonnie reappears and unhinges its jaw, biting Oswald's arm and making it bleed. He manages to make the bunny accidentally hang itself on a rope above the ball-pit, which makes his father wake up with no recollection of any of the events. The bunny suit appears empty above the pit, and Oswald's dad notices it. They finally leave Jeff's Pizza, and Oswald never plans to go back into the pit.

The cover of the book

The front cover of the book (on the right) shows Spring Bonnie in the ball-pit, with balls coloured blue, cyan, purple, white, red and yellow. However, in the story the pit was only described to contain red, green and blue balls. Although the artwork for the books is sometimes inaccurate, this ball-pit could show how faded the balls got after being abandoned for 30 years. With closer inspection, you can also see scratches on the balls, further showing how delicate they are due to age.

Additionally, we can see a black liquid pouring out of Spring Bonnie's right eye-socket. In the Stitchwraith Stingers, the Stitchwraith's victims had 'eyes that bled black down the sides of the face'. Theorists believe this black 'blood' to be related to agony (the most powerful but haunting human emotion), which further supports the idea that the antagonist and the Freddy's location in the story may have simply been an agony-induced manifestation.