Alex Mack is an ordinary teenage girl, living with her parents and older sister in the corporate town of Paradise Valley. After her first day of junior high school, while walking home, Alex is nearly hit by a truck from the chemical plant, and during the incident, she is drenched with a top-secret chemical called GC-161. It's not long after when Alex realizes the chemical has done something to her. She now has the power of telekinesis, can shoot electricity through her fingertips, and morph into a silver puddle. She also turns golden yellow when experiencing extreme emotions, a source of much anxiety. She confides only in her sister Annie and her best friend Raymond about her powers and must keep them a secret from everyone else, including her parents, for fear of what the chemical plant CEO, Danielle Atron, will do to her if she finds out.