As long as she has her best friends Allie Einstein and Charlie Darwin by her side, Izzy Newton is ready to take on sixth grade. But Izzy's good mood is ruined when her old friend Marie Curie returns, and she doesn't seem to want to be friends anymore. To make matters worse, the air conditioning at school is on overdrive, and the adults have no idea how to fix it. It's up to Izzy and the S.M.A.R.T Squad to thaw out the school, and Izzy hopes to thaw her relationship with Marie along the way.