" Bionic Showdown " (Season 2, Episode 14) is a pivotal one-hour special in the Lab Rats series that originally aired on August 5, 2013 . It serves as a major turning point, revealing the true origins of the bionic trio and introducing their primary antagonist, Douglas Davenport.
Bionic Showdown Part 1 - Lab Rats (Series 2, Episode 14) - Apple TV [S2E14] Bionic Showdown: Part 1-2
: Douglas Davenport, Donald’s long-thought-dead younger brother, returns to kidnap Donald. He uses Donald as bait to lure Adam, Bree, and Chase into his lair. " Bionic Showdown " (Season 2, Episode 14)
: It is revealed that Douglas Davenport is actually the biological creator and father of Adam, Bree, and Chase. Donald is their uncle, who took them to protect them from Douglas’s plan to turn them into soldiers. He uses Donald as bait to lure Adam,
: The stress of the battle leads to the unlocking of new "hidden" bionic abilities: Adam : Unlocks his Blast Wave ability.
: Marcus is revealed to be an android created by Douglas, possessing all the Lab Rats' powers combined. He is seemingly destroyed at the end of the episode.