
A new bionic sibling is introduced this season, Daniel Davenport. Out of the three, Taylor is the only one still alive, and the only one to join the good side. Marcus Davenport, Taylor and Victor Krane all return this season after the latter two were presumed deceased, while the former was brought back to life after being destroyed. Hal Sparks directed the episodes Left Behind, Spider Island, and Space Elevator. This season features two new sets, the Mentor Quarters and the Davenport Bionic Academy. There was a crossover this season with Mighty Med in Lab Rats vs. This Season introduces a new Big Bad, Giselle Vickers. Leo was given a bionic leg to replace his injured one in Space Elevator. Spikette, along with another student with the Commando App ( Spikette) and Bree's Commando App, ( Spikerella).
This is the most one hour episodes in a season. There were five one-hour episodes (not including the crossover): Bionic Rebellion, Bionic Action Hero, Lab Rats: On The Edge, Space Colony, and The Vanishing.This season makes Lab Rats the 2nd Disney XD series to make it to Season 4.It also features an updated beginning to the intro. This season is renamed to Lab Rats: Bionic Island.This is the only season that premiered in March.Jessalyn Wanlim as Giselle Vickers (4/26).Jeremy Kent Jackson as Douglas Davenport (15/26).Tyrel Jackson Williams as Leo Dooley (26/26).Kelli Berglund as Bree Davenport/ Spikerella (26/26).Spencer Boldman as Adam Davenport (26/26).
Billy Unger as Chase Davenport/ Spike (26/26). And Then There Were Four (418) - January 13, 2016. Ultimate Tailgate Challenge (413) - December 2, 2015.
The Curse of the Screaming Skull (420) - October 21, 2015.Simulation Manipulation (406) - April 22, 2015.Official promotional image for the first half of the season.