Paige’s estranged mother calls on Team Scorpion when she accidentally uncovers a forgotten nuclear reactor on the verge of exploding.

While on a mission to repair a turbine at a wind farm, Team Scorpion must race to save Paige and Happy before the cable holding the gondola they are in snaps and sends them plummeting to the ground.

Team Scorpion must work with their old nemesis Mark Collins in order to prevent the extinction of mankind. Also, Walter and Paige awkwardly navigate their new relationship.

On Christmas Eve, when Walter chooses work over spending quality time with his friends, he falls down the stairs and hits his head, and as he lays unconscious, he enters a dream world where Team Scorpion never existed.

Team Scorpion must prevent an incoming tsunami from hitting a vulnerable nuclear power facility, and Toby secretly helps his ex-fiancée retrieve her stolen identity.

Team Scorpion must use their high IQs to win a softball game when the homeland director challenges, with all of their future government contracts on the line. Also, Walter’s secret night out with Florence puts Toby and Happy on edge.