The evil Alex wreaks havoc with her friends and family while Annie and Ray try to find the good Alex to recombine the two.
Alex and Robyn get jobs at the new video store in Paradise Valley, where Vince and Dave have installed the plant's latest GC-161 detector.
Nicole tries in vain to petition against the plant for environmental violations. Alex is more concerned about her mysterious next-door neighbor who she sees having suspicious contact with the plant.
Alex becomes a photographer on the yearbook staff to earn extra credit. Louis develops a crush on Annie when she tutors him. Alex uses her powers to get herself paired with Scott on a photo assignment.
Alex and Ray's friendship is in trouble when he gets caught up with his basketball crowd. Meanwhile, the plant plots to get rid of George.
Alex's powers are out of control again and she finds that she has super strength. When Ray takes her for some serious heavy lifting at the construction site, they encounter two unwanted visitors: a suspicious Kelly and a news crew she has summoned to document Alex's mysterious abilities.
Alex experiences a chemical reaction to GC-161--uncontrollable bubbles. This unusual development coincides with the demise of Annie's relationship with Bryce.
In response to Alex's wish to jazz up the school paper, Louis becomes a kamikaze reporter who will stop at nothing to get a good story. This includes selling Ray out. Barbara is a student again and finds her new professor strangely familiar.
Just when Alex is feeling ordinary, she befriends Paradise Valley's new wild child who favors blue hair, tattoos and nose rings. Alex goes wild herself until she realizes the value of her true identity. Vince, fired from the plant, looks for the GC-161 kid himself.
Inspired by ""Cyrano,"" the school play, Louis helps Ray court the girl of his dreams. When she falls for it, Ray has to face two mistakes: his girlfriend is superficial and his superficial charms are about to run out. Alex's attempted rescue makes things worse. Meanwhile, Annie gets an internship at the plant and gets some romantic ideas of her own.
Paradise Valley's radio station has a popular personality, but no one knows his true identity. Alex and Ray get bold and sneak into the station, only to discover how hard it is to live with a secret.
Alex is overwhelmed when an attractive guy starts looking her way. When he requests her as his study partner for ""Romeo and Juliet,"" she can't control her chemical glows. It takes many blushes before she realizes that there is less to him than meets the eye. Things get worse when Dave spies on the kids and assumes that Alex's ""Romeo"" is the GC-161 kid.
Alex discovers that corruption is rampant in the town's ""Woman of the Year"" contest. When she tries an experiment on Louis, Alex gets yet another dose of havoc-inducing chemicals.
Alex has to decide how to handle the attention of a seventh-grade admirer. Vince sneaks into the Macks' house to spy on George's research and gets stuck in the basement.
Math is the ultimate challenge for Alex, and when she starts cheating, she can't stop. For help, she turns to Annie, who steers her back to her senses. However, Dave has been spying on Alex and has begun to question some floating exam books and other mysterious phenomena.
Alex befriends an unpopular guy and finds that her own friends turn on her. She blames them until she realizes the unpopular guy has a thing for her. Ray has an unlikely adventure when Dave helps him pass a driving test.
There is only one problem with Alex's new boyfriend--he's also dating Annie. In what turns out to be an innocent set of circumstances, Alex must walk away from a guy with real potential. Annie's broken heart is made worse by the fact that Barbara is following her around for a science experiment. Alex chooses to be loyal to her sister and dump the guy--at least for now.
Alex's old friends don't like her new friend, and with good reason: The plant has hired the new girl as a spy at the school, and Lars now suspects George is a mole.
While out racing bikes in the woods, Ray and Alex find a recluse who lives in a treehouse. He turns out to be one of the original GC-161 scientists. Vince and Lars learn of the existence of the scientist and Alex, Annie and Ray rescue him from the plant's goons.
A school bully picks on Alex and she must summon all her powers to resolve the ensuing conflicts. Meanwhile, at the plant, George is suspected of espionage when Annie accidentally leaks GC-161 information to Lars.
In a surprising move, Alex tries out for cheerleading...and makes the team! But while she enjoys her new popularity, she misses her carefree life. Louis accidentally switches diskettes with Annie so that she narrowly escapes getting in trouble with the evil Danielle Atron.
After coming to school like every day in her life, Alex notices that her parents, friends and teachers have started to act strangely. First she gets into detention with no reason and after escaping, everybody starts haunting her. But, what is really going on?
Alex has a doctor's appointment and fears her altered body chemistry will be discovered. Robyn grieves over the loss of her hamster.
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.