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, 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.

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

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

A reporter from the Planet newspaper comes to the Macks' house to do a story; Alex's cold makes her powers go haywire.

Annie considers going away to school. Meanwhile, Alex's powers are going haywire and she must convince Annie not to go.

Alex uses her powers to save Ray after he freezes at a school music recital.

Alex and Dad have trouble connecting. They go on a day trip together and chaos ensues.

On her way home from school Alex Mack is practically hit by a truck. The truck is carrying a top-secret chemical and spills it on Alex. Alex learns later that she has magical powers and shares this secret with her sister, Annie, and best friend, Raymond.

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

Louis makes a great effort to impress his old friend, Spivey, including throwing a party at the donut shop which jeopardizes Alex's job. The boys have to learn that friendship involves more than first impressions.

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.

When Alex and Annie are stuck at home during a rainstorm, they reminisce about the value of superpowers and sisterhood.

While trying to impress Bryce, Annie goes mountain climbing and is left dangling.

Alex thinks Scott wants to ask her to the plant dance, but Dad keeps getting in the way.

Alex is upset when Annie agrees to go to the plant carnival with Bryce instead of her. Meanwhile, Danielle must contend with a former employee who has returned to the plant--as a government inspector.

Alex tries to rescue a chimp named Oscar from Vince by secretly keeping him as a pet. Annie is forced to tell George the truth about GC-161.

A morphing accident causes Alex to switch bodies with Barbara. Alex realizes that she's not ready for adulthood. Annie loses confidence about leaving home and talks to George about it.

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.

Ray enters the brutal world of politics when he launches his campaign for eighth-grade President.

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?

Grounded, Alex sneaks out for a game of roller hockey and a night of trouble.

Alex, Ray and Louis rescue a kid trapped under a cement pipe in the park. When Louis accepts all the credit and becomes the town's local hero, he falls under the plant's suspicion of having the special powers.

Alex experiences a chemical reaction to GC-161--uncontrollable bubbles. This unusual development coincides with the demise of Annie's relationship with Bryce.

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.