Team Scorpion and Walter's parents visit Megan in the hospital as her health deteriorates, but they end up quarantined when a deadly fungus outbreak threatens to infect everyone.
The team is blackmailed to break into the United Nations to assist in the assassination of a dangerous arms dealer; and Sylvester makes a bold move to protect Megan's wishes.
Team Scorpion helps the CIA locate a top-secret aircraft in Area 51 in order to raise money for Walter's research to save his sister's life.
The team goes undercover on the set of a superhero movie in Kazakhstan to dismantle a nuclear missile being sold by terrorists.
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.
A tech billionaire hires Team Scorpion to rescue his kidnapped daughter. Meanwhile, some feelings get hurt when Walter gives an interview and fails to acknowledge the other members of the team.
Team Scorpion try to save a boy on Christmas Eve when he gets trapped in a beach-side cave and the rising tide threatens to drown him.
Sylvester is seriously injured when he accidentally triggers an explosive device during an investigation; and Team Scorpion search for who is responsible.
Team Scorpion tries to recover stealth technology before it falls into enemy hands when a military plane is shot down in Bosnia. Meanwhile, Walter's sister takes a break from her MS treatment and spends time at the garage with Sylvester.moreless
Scorpion is called in to save the Governor's daughter when she is somehow "bio-hacked" with a deadly virus and is given 24 hours to live. A letter about his sister, gives the case new meaning for Walter.moreless
Zoe and Joel are frustrated by all the troubles with the remodeling job at their new house. Rose convinces Lavon to agree that BlueBell become sister cities with a town in France. George gets talked into helping Lemon with a business venture, but Wade has to play peacemaker to keep them from fighting. Brick sees an opportunity to become BlueBell’s Man of the Year, but he quickly learns that the competition will be tougher than he expected.moreless
Zoe discovers that Joel has hired some unreliable workers to help renovate their house, and when one gets injured on the job he threatens to sue. Lavon has been organizing BlueBell’s Renaissance Faire to keep himself occupied, but when he has trouble selling the tickets tickets, he decides to use Lemon’s two suitors as the main event. Wade is excited to celebrate his upcoming anniversary with Vivian, but her son has other ideas.moreless
On the island, Damon experiences a violent encounter with a vampire hunter named Vaughn and realizes he is one of The Five. Stefan reveals his feelings about becoming human again to Elena. The group learns a shocking new piece of information about the cure, which changes the situation for everyone. Jeremy helps Bonnie distinguish between reality and illusion, and Shane finds comfort with Caitlin, a woman from his past. Back in Mystic Falls, Caroline and Tyler realize that they'll need Klaus's help as they try to decode the marks on the Hunter's Sword, though Klaus has his own agenda for unlocking the mystery.moreless
Professor Shane leads a group to a remote island off the coast of Nova Scotia, where he believes they will find the secret of the cure. As the group hikes to the island's interior, the rivalry between Rebekah and Elena continues. As Stefan tries to keep the peace, and Damon accuses Shane of leading the group into a trap. Bonnie and Jeremy work to decipher the message of the Hunter's mark, while Shane reveals more about the legend of Silas and the witch Qetsiyah, along with details from his own past. Back in Mystic Falls, Tyler confronts Klaus, and Caroline finds herself in the middle of the ensuing violence.moreless
The team hunt a female fugitive, who may have been assisted by a prison volunteer.