The alien Kozzy decides to bake cookies for his classmates. Unfortunately, his recipe happens to - as a side effect - create a black hole in the middle of their classroom. The human kids must get her to find a different way to create the temperature needed for these special cookies before the earth is destroyed.
Reagan and Luca strive to make Bazz’s first earth birthday a memorable one (he’s actually 2,279 years old on his planet). They do, but under the wrong circumstances. Meanwhile, Benji wants to eat alien food so he can be just like Flurb, eventually selling the other kids on the idea.
Mr. Lancaster is out sick and, through a crazy turn of events, there is no substitute. So Will and SzQoejgouk decide to take over as teachers. They figure out a way to send Jemmifer on a never ending quest for the perfect eraser so they can stay in charge.
Luca has received his most favorite toy in the whole wide world – a ball. Beeveeb, who is always looking to spoil the human's fun, takes the ball and tosses it outside the town’s bubble, resulting in everyone else’s risking life and limb to look for it.
Will gets a pet goldfish. But as it turns out, goldfish are the gods of the planet where Randall lives, so he is convinced that everyone in the town needs to cater to it.
To get a welcome gift for a new alien, Nagol, the class decides to sell off the contents of the classroom. However, they end up unintentionally selling everything in town.
Logan hears (mistakenly) that his best friend Bertbart is going back to their own planet, so he does everything in his power to stop it.
Will’s alien pet (half fish, half elephant) is missing, and the group has to scramble to find it before it escapes the town and reveals their secret to the world.
A school science experiment goes haywire, causing Haley and Thurber to care for some alien atomic particles while the others prepares for a celebration for the school’s principal.
Benji has a new imaginary friend. Only we learn that he is not imaginary. He’s a new alien that’s been there all along, only he’s the size and shape of belly button lint. In fact, that’s where he lives…. In Benji’s belly button.
Some of the human kids mistake an alien puppy for a monster, while at the same time, some of the alien kids similarly mistake a lawn sprinkler for a bigger monster.
The 2nd grade aliens decide to show off by taking their human classmates for a ride in a spare spaceship. But they crash into the town’s bubble which, once again, causes it to fail and jeopardize the secrecy of their existence.