The Bizarre Events at Hellman Elementary

Hellman Elementary has strange teachers and creatures that roam the halls. This is well known to the students, but in elementary school, making friends is what it's all about. Where else can you be friends with a kid who was attacked by a giant squid in the pool?
Friends always help each other, but what happens when your friends begin to change? For instance, if your friend is allergic to tomatoes one day, why isn't she allergic to them the next day? Furthermore, why would fifth graders start acting like kindergarteners?
Payton's birthday is just a couple of weeks away, and he is excited about having his cousin Gabe come to live with his family. However, when Gabe arrives, things take a bizarre turn. Payton doesn't recognize Gabe as the friend he was last year. Also, Payton's friends are hanging out with Gabe and now throwing temper tantrums. Is Payton going crazy? Is Gabe trying to steal his place in fifth grade? Or worse, steal his friends and family?
Is something more sinister spreading through the hallways? Hellman Elementary has a dark and strange past. Payton will have to get to the root of the problem if he wants to make it to sixth grade, or he may be the next bizarre event at Hellman Elementary!