Donald and Douglas reveal that they have built an upgrade for all the students bionics, except for Leo's. But the upgrade doesn't work on Adam, Bree, and Chase because their systems are older. Adam, Bree, and Chase are therefore left at their level, while all the students are much more powerful. Meanwhile, Daniel is brought to the Academy because he had been using his bionics in the outside world. Douglas decides to enroll Daniel at the Academy, and he makes Leo his mentor. Leo steadily tries to teach Daniel, but Daniel proves to be unteachable, so Leo gives him the upgrade as well. The students steadily start to vanish, including Daniel. Giselle Vickers, Douglas' old girlfriend, is revealed to have captured them. Daniel sends a video message to the Island, requesting help.
Lab Rats — Season 4 Episodes (26)
EP 1
E1
EP 2
E2
EP 3
E3
EP 4
E4
EP 5
E5
EP 6
E6
EP 7
E7
EP 8
E8
EP 9
E9
EP 10
E10
EP 11
E11
EP 12
E12
EP 13
E13
EP 14
E14
EP 15
E15
EP 16
E16
EP 17
E17
EP 18
E18
EP 19
E19
EP 20
E20
EP 21
E21
EP 22
E22
EP 23
E23
EP 24
E24
EP 25
E25
EP 26
E26