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.
Davenport's time machine brings Leo, from seven years in the future, to present day to prevent Adam, Bree and Chase from going on a mission from which they'll never return. Davenport takes the warning seriously and forbids the Lab Rats from going on the mission, but they decide to sacrifice themselves in hopes of saving the world. Meanwhile, future Leo teaches present day Leo how to be cool and shows Davenport his fate.
Adam, Bree and Chase defy warnings from Davenport and swap bionic chips. Chase, with Adam's abilities, attempts to use heat vision for the first time and accidentally fries the elevator's circuitry, leaving Leo trapped inside with Principal Perry. After an unsuccessful attempt to return the chips to their rightful owners, the Lab Rats realize they must work together to stop the elevator from plunging to the basement.
When Tasha and Davenport go on a vacation, it is up to Leo to make sure that nothing happens to his stepdad's prized possessions. Leo and the Lab Rats all promise to behave, but the second they're gone, Leo instantly heads to the lab and plays with a new gadget inadvertently causing Adam, Bree and Chase to glitch. However, their fun must come to an end when a Davenport Industries Solar Drone crashes through the window of the great room.
Tasha takes the entire family on a nice 'tech free' beach weekend in the RV, but when Davenport discovers a solar flare headed in the Earth's direction, he secretly enlists the help of the Lab Rats. While Davenport distracts Tasha, the trio is forced to wait in the RV-turned portable lab for their rocket launch window. Cooped up inside during their first summer vacation, Leo and the gang sneak out for a quick jaunt on the boardwalk but when they return the RV is gone.
In order to try and impress Janelle, Leo signs up for a one-on-one basketball tournament against the current reigning champ, Trent. Leo plans to use Davenport's antigravity high-top sneakers to help with his slam dunks, but when the shoes get into the wrong hands, he's stuck playing with his own two feet. Meanwhile, Adam and Bree try out for the cheerleading squad and face the wrath of head cheerleader Stephanie.
While helping Davenport in the lab, Leo accidently unleashes an internet virus transforming the "smart house" computer Eddy into an evil version named Teddy. Meanwhile, Bree hosts her first slumber party and invites popular mean girl Stephanie. Adam and Chase decide to prank the girls, but they are interrupted when Teddy takes over and sends everyone into a panic.
When Adam, Bree and Chase are caught on Principal Perry's surveillance camera using bionics, they enlist Leo's help to pull off their most important mission yet. Donning Davenport's invisibility cloak, Leo sneaks into Perry's office to retrieve the evidence, but their plan is foiled when Tasha and Davenport arrive early for parent-teacher conference night.
While Adam, Bree and Chase head off for their latest mission to fix a broken panel in Davenport Industries' Space Station, Leo is tasked with distracting his nosy nemesis Marcus. When Marcus wanders into the lab, Davenport is forced to cover and answer his prying questions instead of guiding the Lab Rats through their biggest mission yet. Meanwhile, Chase accidently discovers a hidden bionic ability, molecular kinesis, leaving Adam and Bree curious about their own secret abilities.
Chase outsmarts Adam with a prank that shatters not only his aura of invincibility, but his confidence. In turn, Davenport and Chase set up a confidence building faux rescue scenario that backfires and leaves Chase in real danger. Meanwhile, Bree faces Principal Perry's wrath after she uses a new ability called "Vocal Manipulation" to mimic her.
The Lab Rats confide in Leo their frustrations at having to constantly train and their desire to do normal teenage things. Leo explains the concept of going on strike so they face off against Davenport, who then calls their strike bluff and raises the stakes by recruiting Leo as a Lab Rat "scab" for an upcoming demonstration.
Leo performs a magic act to earn a spot in the school talent show but loses his slot to Chase who uses his powers to cheat and create "magic" of his own. Leo then sets out to sabotage Chase but inadvertently releases Chase's rampaging alter ego, "Spike," to wreak havoc on the school. Meanwhile a frustrated Bree watches as Adam and Owen attempt to use butter as art.
In an effort to get out of training duties, Adam enlists Leo's help to create a duplicate Adam using Davenport's experimental cloning device. However, Adam's clone uses the same device to create another duplicate to avoid going to school and the clones he creates repeat the same process resulting in a mob of ever duplicating Adams.
Since the lab is destroyed, Adam, Bree and Chase go without their capsules. This causes glitches in their bionics. In order to prevent this, Mr. Davenport pulls off a huge stunt in a fiberglass jet wing he invented. Things go wrong when the Jet Wing runs out of fuel. Meanwhile, knowing the Lab Rats' bionic secret, Principal Perry uses Adam and Bree as her bionic servants for the day.
Since Principal Perry knows that Adam, Bree and Chase are bionic, she wants to get in the action and go on a "Mission" with the lab rats. When they stage a fake mission. They take her down to the newly built lab, things don’t go as planned, and they have to save Mission Creek High from a speeding rocket. Meanwhile, Janelle goes on a date with Leo, but is beginning to see him as a jinx because she always gets hurt when he is around.
Leo's excited about his first high-end technological creation, a pair of attack orbs meant to protect the family, but when they can't differentiate between friend and foe, they create more harm than good. Meanwhile, Chase steals Davenport's Eddy technology to make a "Cheddy" app and win a Tech Town employee contest, but things go awry when the technology glitches.
Leo tries to show off his bionic arm to Janelle. Meanwhile, Agent Graham promotes Adam, Bree and Chase as bionic celebrities. But when they realize they missed a mission because of him, the Lab Rats decide to get Davenport back as their leader by pretending to have glitches in their bionics to humiliate Graham in front of the President of the United States, when he comes to visit them. In the end, Donald is back as their leader after Agent Graham is fired by the President.
Leo and Davenport attend fan convention and face off in an epic fire staff battle. Meanwhile, Adam, Bree, and Chase attend the convention dressed like their favorite "Alien Gladiators" characters in search of the movie's star. However, things take a turn for the worst when the gang lands in a security holding area with a costumed fan boy.
Chase, Adam, Bree and Leo discover that a confidante has secretly formed an evil rebellion to exact revenge for his father's death by killing Davenport, leading to a bionic battle of good versus evil. Meanwhile, Leo is quick to tell all of the other students that he is not "one of them" while bragging about living with Adam, Bree and Chase in their high-tech quarters, which quickly comes back to haunt him.
Davenport gives Eddy a synthetic human body.
Principal Perry brings back a skull from a neighboring island and everyone is convinced that it's cursed.
Racked with guilt over blinding a teammate, Leo moves back to Mission Creek, but his self-exile ends when his family finds itself in extreme danger.
When Tasha gets everyone except Perry tickets to the big game, Perry goes crazy and destroys the tickets.
Everyone is shocked when Douglas introduces a fourth bionic sibling named Daniel who’s been living a normal life with an adopted family.
Donald takes everyone for a visit to "Davenportia," the first human space colony located on a remote planet in another galaxy.
Krane's evil cohort, Dr. Gao, reveals their plan to wipe out and replace Earth's population with a bionic civilization.
The academy students suddenly vanish after receiving an operating system upgrade. The team initially blames a glitch, but realize the kids are pawns in a much bigger master plan. The Lab Rats put their lives at risk when they face off against the vanished students' captors - a nefarious duo they recognize from their past.