- "For what it's worth, when I was young, you were like a father to me. Sometimes you still are."
- —Walter to Cabe
"Rogue Element" is the ninth episode of the first season of Scorpion. It aired on November 17, 2014.
Team Scorpion must help protect Cabe's ex-wife after she uncovers evidence that suggests foul play in the death of a prominent congressman.
A congressman and his aide are out on a boat when it explodes.
At Scorpion HQ, Walter tells them he got a reward for thier good work. Everyone is excited when he opens a crate with an authentic original Proton Arnold video console is revealed. Ralph's father Drew comes by to bring him to school. He speaks to Walter privately, thanking him for the pitching clinic he helped him put on for Ralph. It helped Drew's delivery and he has a tryout with an AA team in Portland. He wants Walter's opinion on what him leaving—or having Paige and Ralph come with him—would do to Ralph. Walter may not be big on emotions, but he looks like a man trying not to seethe.
Cabe Gallo sees Walter's reaction and makes up an errand for them to run together. On the way, Cabe get's a text with an emergency code word and uses evasive driving maneuvers all the way to a low rent hotel. He knocks on a door and his ex-wife Rebecca opens it. He hasn't heard from her in 15 years, but she's in-house counsel for a lobbying firm and stumbled on something illegal and is now in trouble.
Cabe notices Walter lurking outside and drags him in. Rebecca found a file about a wire transfer that looked like money laundering on her work computer. She put it on a flash drive but was stopped by security on the way out. She managed to drop the drive in a planter but when she got home she saw a man in a mask coming out of her bedroom. She ran.
Cabe takes Rebecca back to Scorpion HQ and gives the team the code on the wire transfer file: CA 79 SE. They're brainstorming when they see the news about the Congressman's boat exploding. He was the California (CA) congressman from the 78th district. SE could be special election. The person who created the account was raising money before he was killed. They deduce that the Congressman was assassinated. Sylvester asks Cabe if it's time to bring in reinforcements, but given the size of the lobbying firm, Cabe wants to keep their efforts completely off the grid.
Walter rigs Rebecca's ID card to get access to her building to get the flash drive she ditched at work. Cabe lends Happy his badge to check out the boat explosion. His ex-wife's exhibits surprise at his actions, but he tells her that the rules go out when they put her life in danger. He can't leave because by his side is the only safe place for her.
Waiting outside Rebecca's office, Paige sees a photo of a young girl in Rebecca's wallet and learns it's Amanda, Cabe and Rebecca's daughter who passed away. In the office, Walter runs into a security guard before he can grab the drive. Despite Cabe's insistence that he get out of the office, Walter determinedly stalls long enough to grab it, hit the guy and run. He locks himself in an office and lowers himself down using a window washer's rig. When the goons cut the motor to the rig, Walter does some calculations and jumps the rest of the way down into Cabe's car through the sunroof.
Cabe angrily yells at Walter, demanding to know why Walter didn't leave. Walter states that they needed that thumb drive and it was too important to leave there. Cabe is upset that they know who Walter is now because of surveillance, and that he risked Rebecca's life as well as his own.
At the marina, Happy examines the charred boat. She finds a clean pipe that should be dirty given how the boat exploded. It means someone installed it after the explosion, so they just need to find out who bought it. When the team returns to the garage, they find it's been trashed. Whomever went through the place took all their electronics. Walter makes everyone leave their current phones on the table as Happy distributes burner phones to replace them. Paige tells Cabe she'd going to call Drew to get Ralph out of school.
Cabe drives the team to a house out in the country. It's boarded up and empty. Once they break in, Walter gets to work trying to link the hose purchase to an employee at the lobbying firm.
Walter talks to Rebecca privately, confirming they're in her old house. With a lead on the hose purchase, Walter gives Cabe Rebecca's flash drive, telling him there are letters to him on it from Rebecca as well. Cabe sits with Rebecca, who remembers the house as the place where their daughter died. Cabe gives her the drive back. She goes outside to get some air.
They review the surveillance footage from the boat supply store where the hose was purchased and find a man named Anthony Cole buying it. He's a brother of an executive at SunDorna Farms, a huge agribusiness. The congressman that was assassinated was in favor of water rights for small farmers, totally contrary to SunDorna's interests. They stood to lose over $5 billion if the bill went through. Cabe thinks they have enough to go to the FBI. They hear Rebecca screaming for help outside and race out to see a car driving off with her. The cars on their tires are slashed so Cabe runs to an old car in his garage and Happy gets it running.
Cabe and Walter hop in the car while the rest of the team hacks into freeway surveillance and tells them which direction to go to follow. They catch up and the kidnappers open fire. When the kidnappers take an exit at the last second, Cabe swerves and crashes into water barrels that line the ramp. Walter borrows Cabe's badge to commandeer another car. They catch up again. Walter's driving because Cabe cracked his head. The team gives Walter the right specs to stop the kidnapper's car with a PIT maneuver and he crashes into the cars bumper at just the right angle to disable it. Cabe holds his gun on the kidnappers as help arrives. Rebecca is unharmed.
Back at Scorpion, Cabe apologizes to Rebecca for abandoning her after their daughter died. She tells him he's the love of her life, but she has a new family—and so does he (the Scorpion team). Rebecca hugs Walter good-bye, telling him to take care of Cabe. Cabe regrets losing his chance to be a father, but Walter tells him he was always like a father to him. Cabe and Walter grab a burger and Walter mentions the hypothetical of Drew taking Ralph somewhere. Cabe cautions him to wait it out.
- Elyes Gabel as Walter O'Brien
- Katharine McPhee as Paige Dineen
- Robert Patrick as Cabe Gallo
- Eddie Kaye Thomas as Toby Curtis
- Jadyn Wong as Happy Quinn
- Ari Stidham as Sylvester Dodd