Against Cabe's advice, Team Scorpion heads to Las Vegas for a simple casino job, but a robbery leads to Walter's arrest and the rest of the team is left to clear his name.

To fix a Los Angeles nuclear reactor that's on the verge of a cataclysmic meltdown, Walter and the team must reluctantly enlist the help of a troubled former member.

Team Scorpion must stop a sabotaged runaway subway train with Paige and Ralph on board. Also, in his attempt to impress Happy, Toby has his first boxing match.

Team Scorpion goes to Chernobyl to repair the decaying nuclear reactor before a catastrophic meltdown, but must also save Sylvester and Paige when they become trapped inside.

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

When a mission in the desert results in exploding shrapnel that seriously wounds Cabe, Team Scorpion must freeze his body in order to save his life.

When a simple mission to protect a vital seed bank goes awry, Team Scorpion must save Happy, Sylvester and Cabe, who begin suffering from life-threatening, fear-based hallucinations.

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.

Paige’s maternal side goes into high gear when Team Scorpion must save an unconscious, hypothermic boy stuck in the wheel well of their airborne airplane. Also, Walter’s white lie to Paige starts to take a toll on him, and Paige realizes something’s up.