Leo is an ordinary teenager who has moved into a high-tech "smart'' house with his mother, inventor stepfather and Eddy, the computer that runs the house. Leo's life becomes less ordinary when, one day, he discovers a secret underground lab that houses three experiments: superhuman teenagers. The trio -- Adam, the strong one, Bree, the fast one and Chase, the smart one -- convinces Leo and his parents to let them leave their lab and join Leo at school, where they try to fit in while having to manage their unpredictable bionic strengths. As Leo figures out a way to keep his new pals' bionic abilities a secret, they help him build self-confidence.
Leo discovers three teen super-humans Adam, Bree and Chase, living in a secret underground lab in the high-tech home he shares with his inventor stepdad, Donald Davenport, his mom, Tasha, and Eddy, the "smart house" computer. Leo takes the trio to school, but when they are unable to contain their bionic abilities on campus, Davenport sends them away to a remote secret lab and now Leo must find a way to save his new friends.
The trio has switched places with robot versions of themselves, sending the robots to the remote lab. Tasha is afraid of Leo's attachment to the 'robots' and convences Donald to send them to the scrap yard. Leo heads off to rescue his new friends. On their return home Donald agrees to let them stay and learn about normal human life if they and Leo can keep their bionic powers a secret.
On the Lab Rats' first day of school, all goes awry when Chase is confronted by a football player and his "Commando App" is triggered, transforming him into Spike, an unruly drill sergeant. When Spike defies the school principal, she pits the Lab Rats up against the football team to battle it out for the coveted cafeteria table
When Leo needs help asking a girl to the school dance, Adam and Chase step in to help, but the plan backfires when she falls for the wrong brother. The boys decide to settle their differences on the dance floor and each show off their best moves. Meanwhile, Bree gets to know her crush, but he gets to know her glitche
The Lab Rats get their first mission to stop Davenport's hi-tech super fast train from speeding out of control. Leo sneaks along, but when the Lab Rats discover he accidently discarded the braking system they were supposed to install, they must improvise a way to stop the train before it crashes into a nearby town. Meanwhile, Tasha is given her big break at the TV news station when her boss asks her to cover the runaway train.
When Davenport's prized invention, a super strength and laser empowered exoskeleton suit, malfunctions, after Chase reverses its controls, to get back at Leo for stealing his presenting job. However, it ends up unleashing destructive power on the household, making Leo's grandma even more suspicious of the family.