Zack, the new kid in town, finds that even a simple trip to school becomes an adventure when he meets Milo Murphy. Milo, Melissa, and Zack try to protect an egg for a science experiment.
Sara wants to see The Doctor Zone Files movie with Milo, but worries about potential problems. Milo and the gang spend the entire day chasing after his doctor's note.
Melissa and Zack throw Milo his first surprise birthday party, the only real birthday party he's ever had. Milo, Melissa and Zack go with their classmate Amanda to an opera concert for extra school credit.
While trying to ensure that the pizza they ordered arrives safely, Milo, Melissa and Zack start sharing secrets. Milo, Melissa, and Zack compete for the school against another school in the acadecamathalon, combining academics and sports.