Guys, there is still a rebel living among us.

Under Siege” is the 4th episode in Season 4 of Lab Rats: Bionic Island. It first aired on April 1, 2015. This is the 76th episode overall. It features the last appearance of Kerry Perry.


When a series of suspicious events happen overnight at the academy, the team is convinced that a new threat has emerged. While Kerry was visiting, they confront her, who is their first suspect. However, later events led them to believe one of Sebastian's rebels is still in the academy.


Main Cast

Recurring Cast

Mentioned Cast

Absent cast


  • This episode is part of the "Wednesday Blackout".
  • This episode takes place about a year after late Season 2.
  • Hal Sparks, who plays Donald Davenport, is absent in this episode for the first time in Season 4. No explanation is given for his absence, but it's possible he left Douglas in charge
    • It is implied that Donald trusts Douglas more with the Academy than the Lab Rats due to what happened in Adam Steps Up..
  • This is the first episode Douglas appears without Donald.
  • This is Spin and Bob's first absence ever since they were introduced. (First Day of Bionic Academy)
  • The Lab Rats suspected there was another rebel in the academy after the events that happened overnight.
    • It is revealed that it was Leo attacking the academy and the others. It is also revealed that he sleepwalks due to his arm glitching since he does not have a capsule. Douglas did not
      LB 01
      think Leo needed a capsule, because he isn't fully bionic.
      • Douglas did make Leo an arm capsule at the end of the episode.
        • The idea of this was an April Fool's Prank to the viewers.
  • This is Douglas' first appearance in Season 4.
    • It is revealed Perry still has a crush on Douglas, while he does not like her back.
    • Perry sang Douglas a lullaby.
  • This is Kerry Perry's first appearance ever since Adam Up.
    • The events that happened in Adam Up were mentioned again by Leo, Bree, and Chase.
      • Douglas, Leo and Adam are introduced to her for the first time, and their belongings end up being stolen by her.
      • It is revealed that Kerry has still not changed. She is still mean to the others.
  • This is the first time the Academy is seen during the night.
  • Leo served as the main antagonist in this episode.
  • Given that Leo was sleep walking when the Lab Rats found out he was the one attacking them, it suggests Leo was sleeping on the job.
  • Adam reveals that Leo is around 5'7.
  • At the end of this episode, Kerry ends up in jail/juvenile detention.
  • There is a reference to what Kerry said in Adam Up.

Cultural References

  • Douglas contending with Leo's malfunctioning arm is likely a nod to the video game Call of Duty: Advanced Warfare, where Joker, who was also portrayed by Jeremy Kent Jackson, had to deal with the protagonist's malfunctioning prothetic arm.


  • In this episode, Chase's bionic hearing is shown as a passive ability, as he was able to hear Bree texting through his comms. In previous episodes however, it's portrayed as an ability he has to consciously activate.  
  • When Chase confronts Bree about texting during their early morning surveillance of the Academy, Chase didn't have a phone with him. After Bree sent him a text, there appears to be a phone strapped on his right leg of his mission suit.  


Lab Rats 'Gallery'
The image gallery for Under Siege may be viewed here.


For a full transcript of Under Siege, click here.


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My favorite episode is
Under Siege!

Code: UnderSiege


Lab Rats Bionic Island - "Under Siege" Clip - Leo's Arm Capsule

Lab Rats Bionic Island - "Under Siege" Clip - Leo's Arm Capsule

Lab Rats Bionic Island - "Under Siege" Clip - Leo Sleepwalking

Lab Rats Bionic Island - "Under Siege" Clip - Leo Sleepwalking

Wednesday Blackout - Disney XD Official

Wednesday Blackout - Disney XD Official

Start a Discussion Discussions about Under Siege

  • Capsules

    • Why were the hexagons in Adam, Bree, and Chase's Capsules blue?
  • New abilities

    • How many people think that leo should get a new ability in the upcoming show? Comment new abilities that leo have........i would like for leo...
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