Season 4 Episode
- Season 4 Bionic Rebellion (1)
- Season 4 Bionic Rebellion (2)
- Season 4 Left Behind
- Season 4 Under Siege
- Season 4 Bionic Dog
- Season 4 Mission Mania
- Season 4 Simulation Manipulation
- Season 4 Forbidden Hero
- Season 4 Spider Island
- Season 4 Spike vs. Spikette
- Season 4 Lab Rats vs. Mighty Med
- Season 4 Space Elevator
- Season 4 Bionic Action Hero (1)
- Season 4 Bionic Action Hero (2)
- Season 4 One of Us
- Season 4 Bob Zombie
- Season 4 Human Eddy
- Season 4 The Curse of the Screaming Skull
- Season 4 On the Edge
- Season 4 Ultimate Tailgate Challenge
- Season 4 And Then There Were Four
- Season 4 Space Colony
- Season 4 The Vanishing (1)
- Season 4 The Vanishing (2)
Lab Rats - Season 4 Episode 4 Under Siege
8.09 22 minutes When suspicious events happen overnight on the bionic island, everyone is convinced a new threat has emerged. However, this threat is revealed to be Leo, when his bionics glitch because Douglas never gave Leo a capsule.
