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.

Team Scorpion is tasked with uncovering a mole inside the CIA who is being coerced into stealing deadly chemicals. Paige gives Walter a flirting lesson in preparation for the case.

Team Scorpion must jog the memory of an injured former Secret Service agent to prevent nuclear weapons from being launched. Meanwhile, Paige is torn when Drew suggests that moving to Maine might be the best for Ralph.

Team Scorpion goes undercover on a cruise ship to locate and disable deadly stolen rockets. Meanwhile, as Valentine's Day approaches, Toby and Happy help Ralph, who is in the throes of his first crush.

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.

Team Scorpion goes undercover at a university to find a hacker who infiltrates the Federal Reserve and threatens to collapse the world economy.

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.

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

The team members set aside their personal and romantic issues when hackers take over targeted U.S. military aircraft and war ships, pointing the weaponry at American cities.

When Walter is accidentally launched into space in a rocket, he hallucinates about Paige as his oxygen runs low, and Team Scorpion works feverishly to find a way to bring him home before he suffocates.

Team Scorpion must find a boy from Ralph’s class who goes missing on a field trip after he accidentally has a run-in with a deadly criminal. Also, Toby gets closer to finding out the identity of Happy’s husband.

Team Scorpion’s simple job at the Los Angeles Natural History Museum turns deadly when they discover thieves robbing a rare gem exhibit in order to get materials needed to enrich a nuclear bomb.

On Election Day, as democracy hangs in the balance, Team Scorpion is called on when someone tries to throw the U.S. presidential election into chaos.

When Team Scorpion travels to Ireland for Megan’s one-year memorial, Walter discovers that a nearby lake’s natural disaster has created a poisonous cloud that could kill everyone in the village. Also, Cabe and Toby try to alleviate the tension between Tim and Walter.

Paige’s estranged mother calls on Team Scorpion when she accidentally uncovers a forgotten nuclear reactor on the verge of exploding.

Walter must swim through the deadly La Brea Tar Pits when Team Scorpion helps a woman trapped in the tar before she runs out of oxygen.

It’s Christmas Eve and Team Scorpion’s electronics-free mountain getaway turns deadly when they come across gun-runners, and Ralph is kidnapped when they try to escape.

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.

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.

Team Scorpion must save a man teetering on the edge of a massive sink hole that threatens to destroy the Los Angeles water supply forever.

Walter and Sylvester enter an international chess competition under cover on foreign soil for Team Scorpion in order to extricate a U.S. spy before her identity is exposed.

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.

While on a mission to repair a turbine at a wind farm, Team Scorpion must race to save Paige and Happy before the cable holding the gondola they are in snaps and sends them plummeting to the ground.

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.

Team Scorpion gets trapped inside a failing and dangerous biodome designed for Mars while trying to extract a pair of scientists inside.

While en route to Toby and Happy’s honeymoon, Team Scorpion’s plane crash lands on a remote deserted island, leaving them all with little hope for rescue.

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.

While decommissioning an old nuclear missile, a simple accident causes Team Scorpion to endure exposure to toxic vapor while trying to prevent the nuke from detonating. Also, Paige confronts Happy about constantly tagging along with her and Walter.

While attending a tech convention, Team Scorpion is taken hostage by a group attempting a virtual heist.

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.

While tracking a device that can prevent a nuclear meltdown through the Los Angeles sewers, Walter learns the nuances of listening and not offering advice to Paige. Also, Team Scorpion meets Florence, their new neighbor at the garage, after she sends a mix of smelly chemicals through their shared ventilation as a warning to keep the noise down.

For Sylvester’s birthday, Team Scorpion visits a renaissance festival, but the revelry is cut short when a group tries to rob a nearby police evidence locker. Also, Paige grows weary of Walter’s play-by-play of all the historical inaccuracies at the festival

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 Cabe’s trial looms over Team Scorpion, a simple case goes sideways when they help a father and his daughter whose plane crashes nearby. Also, Paige helps Walter navigate his feelings about Cabe’s possible future in prison.

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.

On Christmas Eve, when Walter chooses work over spending quality time with his friends, he falls down the stairs and hits his head, and as he lays unconscious, he enters a dream world where Team Scorpion never existed.

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.

On Valentine's Day, Team Scorpion must set aside their romantic plans to help a doctor and pilot trapped inside a helicopter that crashed atop a skyscraper. Also, Toby and Happy wait for news on their fertility results, and Sylvester realizes that he may have feelings for Florence.

Team Scorpion inadvertently crashes a bank robbery in progress and is taken hostage. Also, Sylvester’s feelings for Florence grow.