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. Also, Paige and Walter must face their feelings for each other after hospital footage reveals Paige kissed him.
Team Scorpion heads to Cuba when a woman from Cabe's past pleads for him to help catch a Serbian war criminal.
In order to save the lives of three judges, Sylvester goes undercover in a federal prison but Team Scorpion must break him out when his life is threatened.
Walter, Cabe and Happy are trapped with the crew in a top secret submarine when an explosion sends it to the bottom of the ocean with limited oxygen and a self-destruct function that will soon activate.
Team Scorpion goes undercover on the "Super Fun Guy" movie set in Kazakstan in order to disable a soviet era nuclear missile being sold by terrorists.
Walter's attempt to "normalize" goes horribly wrong when a nefarious virus is uploaded to his computer, turning Team Scorpion's new "smart" building project into a burning death trap with people locked inside
Team Scorpion must stop a sabotaged runaway subway train with Paige and Ralph on board. Also, in his attempt to impress Happy, Toby has his first boxing match.
To help fund Walter's research into saving his sister's life, Team Scorpion takes a lucrative job for the CIA to find a top-secret aircraft in the mysterious Area 51.
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.
When Team Scorpion and Walter's parents visit Megan in the hospital as her health deteriorates, they are quarantined after a deadly fungus outbreak threatens to infect everyone.
Team Scorpion goes undercover at a university to find a hacker who infiltrates the Federal Reserve and threatens to collapse the world economy.
On Christmas Eve, Team Scorpion must prevent a catastrophe when torrential rains create a large crack in a dam, threatening to wipe out an entire town in its wake.
In order to save a United States Special Forces unit from certain death, Team Scorpion must brave the subzero temperatures of Antarctica. Also, when Happy becomes cut off from the team and lost in a blizzard, Toby risks his life to find her.
Sylvester comes face to face with his estranged father, a retired general, 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.
After a powerful earthquake rocks Los Angeles, Team Scorpion must fix a pinched gas line to prevent a massive explosion.
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.
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.
While on a secret mission in Djibouti, Africa, with his new Homeland protégé, Cabe is captured and Team Scorpion must save him.
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.
Team Scorpion goes to Chernobyl to repair the decaying nuclear reactor before a catastrophic meltdown, but must also save Sylvester and Paige when they become trapped inside.
Team Scorpion must outthink their unstable ex-Scorpion member, Mark Collins, after he kidnaps Toby and threatens to kill him unless his cunning demands are met.