Alex asks her sister for help with a class science project, but ends up using her power to impress the teacher. This gets her into trouble when the teacher believes that the project was done by Annie, not Alex. Meanwhile, Dave and Vince disguise themselves as janitors in an attempt to find Alex.

When Robyn joins an environmental group the donut shop is threatened and Alex's friendship with Gloria is tested.

Alex saves a woman's life but can't tell the authorities that she double-morphed the woman to the hospital. The mystery heightens Danielle Atron's suspicions. As Annie prepares for college, a bittersweet realization comes over the sisters who share so much.

Alex struggles in Spanish class with a tough teacher, then struggles with the possibility that she got the teacher fired. Lars sets Dave up to be the first human research specimen for dangerous GC-161.

Alex has a doctor's appointment and fears her altered body chemistry will be discovered. Robyn grieves over the loss of her hamster.

Ray, Louis and Alex form a band and have to deal with issues of leadership, fame and competition. Robyn learns the ""rules"" of dating from Kelly.

Ray is purposely mysterious about his new girlfriend, Rachel, so that Alex won't get jealous. Alex becomes jealous anyway and struggles with accepting a new friend.

Alex becomes friends with the new boy in school, Hunter, who may know something about the GC-161 project.

Robyn moves in with Alex while her parents are away while Mr. Mack suspects that Dave may be his secret GC-161 informant.

The final episode. Ray, Louis, and Hunter try to free Alex and her parents from the Plant which is lined with bombs thanks to Danielle Atron. Meanwhile Dave works with Gino and the FDA to stop the chemical plant from releasing GC-161.