The governor calls on Team Scorpion when his daughter is mysteriously "bio-hacked" with a deadly virus and only has 24 hours to live. The case takes on a deeper significance for Walter after he receives a letter regarding his sister.

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.

When Sylvester accidentally triggers an explosive device during an investigation, Team Scorpion must focus on finding who's responsible even while their friend's life hangs in the balance.

On Christmas Eve, Team Scorpion races to find a way to save a young boy's life after he is trapped in a beachside cave and the rising tide threatens to drown him.

While on a mission to save lost hikers, Team Scorpion’s helicopter crashes, igniting a massive wildfire that quickly closes in on them. Also, Sylvester must help their injured pilot who is unable to make it to safer ground.