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.

After four years of keeping her powers hidden, Alex's secret world is falling apart. As the Plant prepares for the release of GC-161 to the public, her dad loses his job, and Louis discovers her secret powers, and is captured by the Plant.

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 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.

Alex carelessly uses her powers and ruins Annie's interview with MIT. She runs away, thinking everyone would be better off without her.

Alex is split into two manifestations of herself when George discovers a chemical that divides GC-161 into its individual elements.

Alex and George discover that gifts and decorations aren't as important as the Christmas spirit, while Dave's gift to Vince is a chimp that runs amok in the plant.

Junior camp counselor is a new role for Alex, and one for which she's not well-suited. She and Kelly get lost in the woods, are chased by a bear and learn the importance of two words: friendship and rescue. George remembers his own camp experiences with mixed emotions.

The plant closes in when Alex's journal, detailing her powers, ends up in the wrong hands.

Alex, Raymond, Nicole and Robyn notice a new neighbor moving in. It turns out to be Louis Driscoll, a cool-looking kid with a wisecracking attitude. The more Raymond likes him, the more Alex doesn't.

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 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.

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.

Aunt Ashley is everything Barbara isn't: fancy, outrageous, irresponsible, crazy. Alex's wild go-cart ride with her aunt forces Barbara to get tough with both of them. Alex's school work suffers while her spirits soar.

At career day at the plant, Alex is taped using her powers and she, Ray and Annie have to sneak back and get the tape.

Alex, Raymond, and Nicole are facing their first junior high school midterm in history class. Libby, the most popular girl in school, has her own ideas about surviving the midterm and studying isn't one of them. Libby decides to pull the fire alarm right before the exam.

In anger, Alex jeopardizes her mom's job. Later, she tries to make it up to her.

Alex steals a test to help Nicole, who is cracking under the pressure of the exam. At the plant, George discovers that GC-161 has the capability to alter human genetic structure.

Annie aces her English Advanced Placement exam, allowing her to attend a writing class taught by a renowned author. Inspired by her sister's achievement, Alex sets her mind to engage in extracurricular activities in the hope that one will bring her some recognition. She discovers an unusual talent for cow milking and wins the Dairy Decathlon. Meanwhile, Annie experiences her first academic failure.

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.

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.

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.

Annie's science project has been chosen as a finalist for the big science fair to be held at the Paradise Valley Chemical Plant. The whole Mack family is looking forward to spending Saturday at the science fair rooting Annie on, except Alex. Not only is she sick of witnessing Annie's triumphs, but the chemical plant is the worst place for her to be. It's crawling with plant spies who are constantly on the look out for "the kid."

Alex and Ray have a falling-out and Alex is afraid Ray will disclose her secret to the plant.