Leo and Donald escape the elevator. Principal Perry lets them stay at the school temporarily in order to get her money from Donald quicker. The Lab Rats stow away on a cargo ship to hide from the FBI and must choose to either keep quiet or help stop a submarine that will crash into the ship and risk being caught. The Lab Rats decide to stop the submarine, with Chase activating his GPS, revealing the Lab Rats' location. Douglas ends up capturing them, disguised as Donald. Douglas reveals that his new bionic partner is a billionaire named Victor Krane, who wants to destroy the Lab Rats permanently. When Donald calls the Lab Rats and tells them that Principal Perry kept their secret, they return home, only for them to get crazy as a result of the Triton App and attack the family, Leo manages to disable Chase's Triton App when he talks to him and Chase manages to disable Adam and Bree's apps. The Lab Rats and the family later see the demolition that happened to the lab and are upset.

Leo and Donald escape the elevator. Principal Perry lets them stay at the school temporarily in order to get her money from Donald quicker. The Lab Rats stow away on a cargo ship to hide from the FBI and must choose to either keep quiet or help stop a submarine that will crash into the ship and risk being caught. The Lab Rats decide to stop the submarine, with Chase activating his GPS, revealing the Lab Rats' location. Douglas ends up capturing them, disguised as Donald. Douglas reveals that his new bionic partner is a billionaire named Victor Krane, who wants to destroy the Lab Rats permanently. When Donald calls the Lab Rats and tells them that Principal Perry kept their secret, they return home, only for them to get crazy as a result of the Triton App and attack the family, Leo manages to disable Chase's Triton App when he talks to him and Chase manages to disable Adam and Bree's apps. The Lab Rats and the family later see the demolition that happened to the lab and are upset.

Donald shows a new motorcycle to the Lab Rats when they get a video message from Douglas that Krane has lost it and implanted himself with more bionic abilities, abilities even he doesn't know about. The Lab Rats instead believe this to be a trap, leading Donald to activate a new security system that only he can bypass. While Leo is at Mission Creek High School, Douglas arrives and tries to appeal to Leo by reminding him that he knew about Douglas and Marcus before the rest of them. Douglas then shows Leo video footage of Krane implanting himself with bionics and asks him to call his brother to prove his honesty. Back at the lab, a transmission comes in and shows Leo and Tasha captured. While Donald thinks it's Douglas, Krane reveals himself on-screen as the captor and demands that the Lab Rats arrive in 10 minutes. While the Lab Rats want to rescue them, Donald heads out alone with an extremely powerful thermal blaster. Donald arrives at Krane's lair, only for Krane to siphon the power from the blaster, rendering it useless and quickly beating Donald with super strength and molecularkinesis. During the battle, Leo and Tasha are trapped in an exothermic energy field to fry them. Afterward, Krane geo-leaps to the lab, allowing Donald to use the thermal blaster to suck in the heat to set Leo and Tasha free. As Chase works to deactivate the security system, Krane arrives and easily beats the Lab Rats with his more advanced bionics. Before Krane can finish them off, Douglas arrives and blasts Krane with a laser blaster. Although he saves the Lab Rats, Krane quickly recovers and knocks him down with another force wave. As he once again prepares to attack, Chase repels his blast back at him with a force-field, defeating him for good. Douglas plans to capture the unconscious Krane, but Donald arrives and blames the entire mess on him. Unfortunately, Krane geo-leaps out of the house and Donald demands that Douglas leaves.

When the Lab Rats are on a mission, it is revealed that a girl was secretly recording them behind a bush. The next day, the Lab Rats go to school and everyone is looking at a viral video called The World's First Bionic Humans. They go back home to tell Donald, but he says he already knows. Meanwhile, Chase is confused that he didn't notice the girl who filmed them behind the bush, even though he thermal scanned the whole place. He then looks at a chip log and finds out that the girl was in the exact spot he scanned. Chase then goes to tell Donald, but a swarm of government agents surrounds them. Leo and Douglas are still in the lab, but they use a trap door to escape and go to school to stay safe. It is then revealed that the mission the Lab Rats were on was a setup. Krane then shows up with the girl who filmed the Lab Rats, whose name is revealed to be S-1. It is also revealed that she is bionic. Krane electrocutes Principal Perry and Douglas while S-1 crushes Leo's arm. Later, Douglas and Principal Perry help Leo to get his arm fixed and take him to the hospital. Tasha later shows up, only to realize that Leo is gone. While the Lab Rats are saying their goodbyes, Special Agent Graham tells them it's time to leave, but Adam refuses. Agent Graham orders his agents to take them down, but Adam uses his wave blast ability to knock them down. When they run to the hospital, Principal Perry tells them Krane is responsible for exposing their bionics. Meanwhile, Leo is in Douglas and Krane's old warehouse and Douglas tells him to take his bandage off and pretend to throw a ball. He then realizes that Douglas upgraded his right arm with bionics. Krane then shows up and knocks down Leo and Douglas. The Lab Rats then show up with Donald, as Krane uses a powerful bionic ability that knocks out Leo, Donald, and the Lab Rats. Krane then paralyzes Donald with his choking ability. Bree battles S-1 while Adam and Chase battle Krane, but he easily takes them down with his newly upgraded Triton App that he uses on S-1. Leo then uses his bionic arm to take down Krane. As Agent Graham arrives, Douglas reveals that Krane and S-1 are the bionic villains. Agent Graham is then saved by Bree as Krane tries to attack him and he takes Krane and S-1 into custody and locks them in a prison with a bionic signal interrupter, preventing them from using their bionics to get out. Later, the Lab Rats are at a press conference and reveal that they are bionic superhumans. While watching it, Principal Perry makes new friends with the Lab Rats. In the end, Agent Graham tells Donald he's now in charge of the Lab Rats. It is also revealed that Krane has an army of bionic soldiers, which he will use to destroy the Lab Rats.

When the Lab Rats are on a mission, it is revealed that a girl was secretly recording them behind a bush. The next day, the Lab Rats go to school and everyone is looking at a viral video called The World's First Bionic Humans. They go back home to tell Donald, but he says he already knows. Meanwhile, Chase is confused that he didn't notice the girl who filmed them behind the bush, even though he thermal scanned the whole place. He then looks at a chip log and finds out that the girl was in the exact spot he scanned. Chase then goes to tell Donald, but a swarm of government agents surrounds them. Leo and Douglas are still in the lab, but they use a trap door to escape and go to school to stay safe. It is then revealed that the mission the Lab Rats were on was a setup. Krane then shows up with the girl who filmed the Lab Rats, whose name is revealed to be S-1. It is also revealed that she is bionic. Krane electrocutes Principal Perry and Douglas while S-1 crushes Leo's arm. Later, Douglas and Principal Perry help Leo to get his arm fixed and take him to the hospital. Tasha later shows up, only to realize that Leo is gone. While the Lab Rats are saying their goodbyes, Special Agent Graham tells them it's time to leave, but Adam refuses. Agent Graham orders his agents to take them down, but Adam uses his wave blast ability to knock them down. When they run to the hospital, Principal Perry tells them Krane is responsible for exposing their bionics. Meanwhile, Leo is in Douglas and Krane's old warehouse and Douglas tells him to take his bandage off and pretend to throw a ball. He then realizes that Douglas upgraded his right arm with bionics. Krane then shows up and knocks down Leo and Douglas. The Lab Rats then show up with Donald, as Krane uses a powerful bionic ability that knocks out Leo, Donald, and the Lab Rats. Krane then paralyzes Donald with his choking ability. Bree battles S-1 while Adam and Chase battle Krane, but he easily takes them down with his newly upgraded Triton App that he uses on S-1. Leo then uses his bionic arm to take down Krane. As Agent Graham arrives, Douglas reveals that Krane and S-1 are the bionic villains. Agent Graham is then saved by Bree as Krane tries to attack him and he takes Krane and S-1 into custody and locks them in a prison with a bionic signal interrupter, preventing them from using their bionics to get out. Later, the Lab Rats are at a press conference and reveal that they are bionic superhumans. While watching it, Principal Perry makes new friends with the Lab Rats. In the end, Agent Graham tells Donald he's now in charge of the Lab Rats. It is also revealed that Krane has an army of bionic soldiers, which he will use to destroy the Lab Rats.

The Lab Rats plan to gain good publicity by having cameramen film them during a mission, but it turns into a disaster when they fight for screen time. After the mission, the president orders the team to stay away from the public in order to let him settle things down. However, it goes wrong when Leo and Principal Perry are holding back angry protesters who want the Lab Rats gone, and Leo accidentally uses his bionic arm. As the protesters become even more enraged, they try to storm the house; Adam panics and uses his bionic super breath to blow everyone off the premises. However, Chase criticizes Adam's actions and the Lab Rats start fighting. They eventually decide to break the team. Three weeks later, the Lab Rats refuse to talk to each other, but they are forced into action when Krane plans to use his Triton App on everyone in the world. A large battle ensues, pitting Leo, Donald, Douglas, and the Lab Rats against Krane and his bionic army. Most of the soldiers attack Adam and Bree, who manage to take them out. Chase has a one-on-one battle with S-3 and Leo has one-on-one battle against S-1. Donald and Douglas attack the soldiers surrounding the satellite, but Krane keeps them from getting too close. Eventually, the Lab Rats and the rest of the team manage to hold back many of the soldiers, but they are running out of time to stop Krane. Douglas then reveals that the Lab Rats can fuse their abilities to stop Krane. They succeed, blasting Krane into the sky and breaking his control over the soldiers. However, their victory is cut short when they find out that Donald is in serious condition after the battle. Later they find out that after the surgery, Donald is still in a very delicate condition. Leo is made an official member of the Lab Rats and gets an upgrade to his bionic arm.

In the middle of a massive heat wave, the whole family is going to space to see Donald's space colony, called "Davenportia". Adam annoys Chase while Chase tries to give his safety instructions and accidentally blasts them into space. After leaving the solar system, they initiate hyper-speed and land on the planet Lithios. In the dome, it's discovered that Perry sneaked her way in with the rest of the colonists.