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.

Team Scorpion’s job to find sunken treasure goes awry when Walter and Paige’s boat explodes, leaving them lost in the middle of the Pacific Ocean surrounded by sharks.

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.

Following a severe storm, Happy’s friend Ada, who lives in a sterile bubble to protect her compromised immune system, is left with dangerous debris on the verge of puncturing the structure. Now, Team Scorpion works to safely move Ada to a more secure location without risking her life.

Team Scorpion must defy the orders of a foreign government after they retrieve an asteroid from space containing DNA strands that could have deadly consequences once exposed.

When poachers almost kill a pregnant endangered deer, Team Scorpion recreates the animal’s womb to try to save it and its baby’s life. Also, Happy and Toby discuss the future of their family.

On Thanksgiving, Team Scorpion's new neighbor, Florence, joins them at sea on a mission to destroy a floating island of trash, but her flawed contribution leaves her, Walter and Happy stranded on the quickly dissolving island. Also, Toby works with Cabe to uncover the details of his father's death that he has suppressed since he was a boy.

As Team Scorpion anxiously awaits the verdict of Cabe’s trial which could send him to prison, they focus their nervous energy on trying to save a dog stuck in a cistern.

A solar storm knocks out power in Los Angeles, and Team Scorpion must help a teen pilot and his girlfriend who are lost over the Pacific without navigation or radio contact. Also, during the crisis, Walter must look after a group of Ralph’s classmates, and Cabe tries to tell Allie finally that he loves her.