The cover shows Slappy sitting on a broken chair with his son.
Jackson Stander is a good kid. His parents and teachers all trust him and know that he would never do anything wrong. But after visiting his grandfather's house and meeting Slappy, Jackson is compelled to do evil things. Slappy has almost all control over Jackson, he even starts referring to him as his son because of all the mischief being caused. Jackson must figure out a way to defeat Slappy. However, when he discovers that his sister Rachel appears to be Slappy's daughter, the question of if he will be Slappy's son starts to arise. So the question is, will Jackson really turn-out to be Slappy's son or not?!
Jackson Stander is a nice kid, with a mean sister named Rachael, they visit their Grandpa Whitman's house, and he gives Jackson a ventriloquist dummy, the dummy is the evil Slappy, in fact, Edgar tells Jackson to get rid of the dummy, he doesn't since it could be fun to bring at the YC.
Jackson finds the words, and he reads them, later in the book, Jackson begins to do really bad things to his friends, and he doesn't know why.
It turns out that he's being controlled by Slappy, who has come to life, when he goes to the YC, Slappy makes Jackson drag Mrs. Lawson across the floor, then Jackson thought that maybe the only way to defeat Slappy, is to read the words on the card a second time, but when he pulls the card out of his pocket, it's blank on both sides, just a blank piece of paper.
A few weeks later, his parents have grounded him and stopped giving him his allowance, and he's banned from the YC, he asked his parents to get rid of Slappy, but they refused and told him to wait until Grandpa Whitman comes to visit, so Jackson puts Slappy in a suitcase, later, he hears his sister talking to someone.
Rachael was speaking with Slappy, it turned out they were working together all along, in fact, Rachael was the one who switched Slappy's spell with a blank card, in the end, Slappy turns to Jackson and says, "guess what? We know how to deal with eavesdropper's" then there's a, "Chirp" sound.
- Some of the story is similar to Horrors of the Black Ring. Jackson Stander is a kind kid who was controlled by an evil villain to do bad things while his sister, Rachel teased him for being a goody-goody. Beth Welch was also a kind kid who was controlled to do evil things while her schoolmate, Anthony Gonzales teased her for being a goody-goody.
- Only difference is that Beth succeeds in the end.
- This is one of the few books in which Slappy succeeds.
- The title is likely a reference to Seed of Chucky