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.

Sylvester goes undercover in a federal prison in order to save the lives of three judges, but the team must help him escape when his life is threatened.

Team Scorpion is blackmailed to break into the United Nations to assist in the assassination of a menacing arms dealer. Also, Sylvester makes a bold move to protect Megan's wishes.

While on a secret mission in Djibouti, Africa, with his new Homeland protégé, Tim Armstrong, Cabe is captured and Team Scorpion must save him.

Team Scorpion is hired by the Department of Defense to break into Fort Knox and “steal” a precious artifact in order to test their security, but they must break in a second time when they find something dangerous hidden inside the object.

Before Halloween, Team Scorpion must infiltrate a deep, vast cave system in order to prevent a bat population from destroying the North America ecosystem. Also, the team dons costumes to stage photos from Halloween’s past for Walter’s upcoming immigration inspection.

When Team Scorpion is duped into producing counterfeit money for a foreign entity intent on ruining the U.S. economy, Paige must rely on her mother Veronica’s skills as a grifter to save them.

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.

At Halloween, Team Scorpion takes on a case to prove the existence of ghosts on the Queen Mary but find an all-too-real disaster when they locate a “ghost ship” on a deadly collision course. Also, Walter considers taking note of Paige’s interests to benefit their relationship.

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.

Team Scorpion heads to the bayou to track down a cagey alligator in order to stop a deadly mosquito-borne virus, and Paige teaches Walter the concept of the “white lie.” Also, Walter hits Cabe with a tranquilizer gun and Toby must save his life, and Sylvester and Ralph help Patty when the mean girls at her school force her to get a dreaded tardy slip.