Class 507 is the worst class Ms. Bryce has ever taught. And she would know -- she's been teaching forever. They are so terrible that when a science experiment goes disastrously wrong (again), Ms. Bryce has had it and quits in the middle of the lesson. But through a mix-up, the school office never finds out.
Which means ... Class 507 is teacher-free
The class figures if they don't tell anyone, it'll be one big holiday. Kyle and his friends...