
Eccentric genius Walter O'Brien leads a group of brilliant misfits who constitute Homeland Security's new think tank, helping defend against the high-tech threats of the computer age. The team -- dubbed Scorpion -- includes behaviorist Toby Curtis, mechanical prodigy Happy Quinn, and statistics guru Sylvester Dodd. While comfortable with one another, the team members struggle with understanding life outside their circle, so when they need help translating societal cues, they rely on the skills of Paige Dineen, a woman with a gifted young son.

While in Ireland for Megan's one-year memorial, Walter discovers a natural disaster at a nearby lake has created a poisonous cloud that threatens an entire village; Cabe and Toby try to ease the tension between Tim and Walter.

When Paige's estranged mother stumbles upon a forgotten nuclear reactor precariously close to exploding, she calls on the team for help.

Walter takes a perilous swim to rescue a woman trapped in the La Brea tar pits; Paige's mother maximizes Ralph's troop cookie sales.

Team Scorpion encounters gunrunners while spending Christmas Eve at an electronics-free mountain getaway; Tim makes a decision about his place on the team.