The new Director of Homeland Security reunites the team when a nuclear powered Russian satellite is knocked out of orbit and must be diverted before it detonates over Southern California.
In order to save the lives of three judges, Sylvester goes undercover in a federal prison. Team Scorpion must break him out when his life is threatened.
Walter's attempt to "normalize" goes horribly wrong when a nefarious virus is uploaded to his computer, turning Scorpion's new "smart" building project into a burning death trap with people locked inside.
Megan's condition gets worse. Walter starts to get frustrated about not being able to help her and in Walter's crazy quest for investors, the CIA appears in the garage with the promise of a big payday.
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.
As Megan's condition worsens, the team gathers at the hospital. As they arrive, they find a pathogen has infected the hospital threatening all of their lives.
The Scorpion team goes undercover at a college to discover who is holding the Federal Reserve for ransom. Walter tries to help Ray, while Paige tries to get Walter to express grief about Megan.
It's Christmas Eve, and Team Scorpion must prevent a catastrophe when torrential rains create a large crack in a dam. They fight to save an entire town from the threat of being wiped out in its wake.
In order to save a United States Special Forces unit from certain death, the Scorpion Team must get through the very low temperatures of Antarctica to connect to a satellite in order to save the soldiers. Toby risks his life to save Happy.
Sylvester comes face to face with his estranged father, a retired colonel, who asks Team Scorpion for help when he believes that a dictator in Africa has uncovered a deadly World War II-era weapon of mass destruction and intends to use it.
Team Scorpion is tasked with helping NASA's top secret rocket launch, but they must sabotage their own mission when Walter's date from the previous night has a bomb strapped to her chest.
While Team Scorpion works to stop an influx of drugs being smuggled into the country via drones, Walter gives Happy and Toby an ultimatum on their new relationship. Penn Jillette guest stars.
After Sylvester scores big on THE PRICE IS RIGHT, Team Scorpion must infiltrate a high-end car smuggling operation about to ship bioweapons to South America
When Los Angeles' blood supply is hacked and deemed unusable because of fear it's been tainted, Team Scorpion must find the culprit in order to save a young girl in desperate need of a heart transplant.
Scorpion is sent on a secret mission to Djibouti, Africa. Cabe is captured. The Team must save him. While Walter has suspicions about the purpose of the mission and concerns over Paige's interest in new Homeland protégé, Tim Armstrong.
Team Scorpion's mission to recover the remains of fallen Marines in Vietnam is threatened along with their lives when a deadly tornado heads directly towards them.
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.