Played by: Elyes Gabel
- Adaptational Attractiveness: Compare Elyes Gabel with this photo◊ of the real Walter O'Brien.
- Ambiguous Disorder: He repeatedly claims to be incapable of emotion and shows signs of being a high functioning autistic.
- Ambiguously Brown: There's no mention of Walter's ethnicity on the show, but his actor Elyes Gabel is of partial Indian and Tunisian descent. In addition, Walter's sister Megan is played by Camille Guaty, a Cuban/Puerto Rican actress, so it can be assumed that the O'Brien siblings are at least non white.
- When we see his parents in the modern day, they're white, but the episode seems carefully lit to hide the difference.
- Walter and Megan are possibly what is known as black Irish, Irish people witsimh black hair and dark Latin complexions, possibly descended from a combination of either Spanish, Berber or Moors. This troper's family is such a case.
- The Atoner: No one actually comes out and says it, but it's pretty clear where Walter's Chronic Hero Syndrome comes from - he's still haunted by those 2,000 civilians who died in Baghdad thanks to his program.
- Boxed Crook: This is averted by Walter's back story. When Walter was eleven, he hacked NASA to download their blueprints for a space shuttle, to print out and hang on his wall. He was put in jail for three days till Cabe could decide if he was a malevolent hacker or not. Cabe decided he was a nice kid, so he let him go and even bought him a new, state of the art computer. Cabe continued to return to mentor the budding genius and groom him as a federal asset.
- Brainy Brunette: He has curly black hair.
- Character Development: Over the first season, his EQ visibly climbs (or rather, Walter starts to get better at admitting he has emotions); nearly always in situations dealing with Ralph and/or Paige. Granted, it takes Toby drawing up a presentation (with a pie chart, a bar chart, and two Venn Diagrams) proving it to get Walter to admit it to himself...
- Child Prodigy: When he was young.
- Chronic Hero Syndrome: If there is anything going wrong in his line of sight, he has to put his two bits in, and if there's anything dangerous to be done, he has to be the one to do it. Unfortunately, he's about as socially sensitive as a honey badger, so people tend to see him as nothing but an Insufferable Genius.
- Case in point, he spends most of episode 3x12 trying to let the team make decisions "democratically" - until at the climax, he figures out a way to keep them from suffocating in a vault filling with explosive poisonous gas that involves someone setting off the gas. Everyone panics and starts arguing as time ticks away, so he pulls rank, sends everyone to safety and sets the explosion off himself. Servant leadership, thy name is Walter O'Brien.
- Citizenship Marriage: He "married" Happy just to avoid being deported. When Walter was granted official citizenship, the two promptly annulled it.
- Deadpan Snarker: After his character development, Walter frequently defaults to snark when he's irritated or upset.
- Defrosting Ice Queen: Mostly thanks to Paige's influence.
- Hidden Heart of Gold: He claims to have no feelings and believes that things like romantic love are pointless, but he has a box of mementos of his sister and of the first time he met Toby and Sylvester, both times where he got them out of bad situations. He's also very protective of Ralph. And let's not forget that the entire reason Scorpion exists is because he wanted to build his own team of geniuses to fix the world's problems, and every time there's anything remotely dangerous to do, he demands to be the one to do it.
- Hollywood Nerd: Very good looking, but with No Social Skills.
- Insufferable Genius: He's a computer whiz with an extremely high IQ, but he's also a cold and arrogant Jerkass. Fortunately, he's getting better, especially with the help he gets from Paige and Cabe.
- Lack of Empathy: He has low EQ, an inability to understand and process his emotions and is possibly on the spectrum, often leading him to say or do hurtful things to people without realizing it. He continually struggles with this problem, both making progress and backsliding throughout the course of the series.
- At the beginning of "Shorthanded", Walter gets a casino employee named Ronny fired—not for dishonesty or incompetence, but because Walter's job is to save the casino money and Ronny's hands are too small to deal cards quickly enough for him to run blackjack often enough to make as much money as the other dealers. Walter and Ronny wind up in the same jail cell and Walter takes the opportunity to lay-out a perfect business plan for Ronny to convert his skill for baking into a successful bakery business.
- This becomes a plot point in "True Colors" as Paige tries to get Walter to act normal because it will help business. His decision to instead state blunt facts about his team's ability becomes vital when the team is sent for psychological evaluation. They pass because the psychologist can see that, even as abrasive as they can be, the family is functioning perfectly and Walter genuinely does what is best for them.
- Martyr Without a Cause: As a result of My Greatest Failure, he is out-and-out suicidal - if someone on the team has to do anything dangerous, he is the first one in. Paige almost leaves because Ralph copies that.
- My Greatest Failure: Back in The '90s, he designed software he for the government at Cabe's request. Cabe told Walt it was for distributing "military aid packages" by air, so he designed it for speed over accuracy; the Air Force used it to carpet bomb Baghdad - killing 2000 people outside the target zone. His stated goal in life is to save at least that many people himself.
- Somewhere in the vicinity of that is his sister Megan's ongoing degeneration from multiple sclerosis. He may be the fourth smartest person in history, but his talents run to computers, not medicine. Every meeting they have is a bittersweet frenzy of love and self-hatred because he can't help her.
- My Sister Is Off-Limits!: Walter is not pleased that Sylvester has begun dating Megan. It turns out this is for Sylvester's benefit, as Walter is very aware that Megan will almost certainly die of multiple sclerosis within the next few years and he knows Sylvester is not exactly equipped to handle an emotional trauma like that.
- Mid-season 2, Sylvester admits he loves Megan, stays bedside with her for months and is there to hold her when she dies. He and Megan also agree to get married so that Sylvester becomes her next-of-kin. Walter wouldn't agree to pull the plug but Sly did because it was what Megan wanted
- Oireland: inverted; he not only does not perpetuate any Irish stereotypes, he is the recipient of one in "Sun Of A Gun" when the African dictator offers him a meal of boiled potatoes and whiskey.
- Pop-Cultural Osmosis Failure: And how. No, Walter, Gilligan's Island is nothing to do with Ryan Duckling.
- Relationship Upgrade: Finally dating Paige as of Season 3's third-to-last episode
- Sibling Yin-Yang: Megan is playful and empathetic while Walter is analytical, methodical, and unable to properly express and process emotions
- Skyward Scream: In "Dominoes", he does this out of sheer frustration when his plan to rescue Owen seems on the verge of failure.
- Surrounded by Idiots: Basically, how Walter thinks of himself every single day in the world. Of course, he neglects the detail that thanks to low E.Q., when it comes to human interaction he's the idiot.
- Tin Man: He emerges as one of these, especially in "True Colors", where he repeatedly reminds people that he makes decisions based strictly on logic. The truth is that Walter is just as susceptible to stress, anger, fear, happiness and a host of other emotions just like everyone else, but often doesn't know how to process or understand them leading him to also often incorrectly state that he has no emotions and doesn't feel anything (often after clearly having an emotional breakdown.)
- "The Reason You Suck" Speech: Receives one from Toby at the end of "Toby or Not Toby," which finally makes Walter realize that he's been an idiot and go after Paige.Toby: What I'm about to say is not fueled by emotion or the worm I just swallowed; it's fueled by my love for you: You, Walter, are a gigantic ass.Walter: Pardon me?Toby: You're so obsessed with keeping this team together, to attach some meaning as to why you are the way you are, that you're willing to sacrifice love for it. I'm gonna make it easy for you. You're a genetic fluke, so freaking what? It doesn't matter! What matters in live is love! And mine just walked out the door. I'm dying inside! I would do anything to make her come back here and say yes. And, you, you jackass! You pushed your love out the door to spend the weekend with another man! A big, sexy, muscled, Navy SEAL man! Comprende, 197?
- UST: Like Woah With Paige until the trailing edge of Season 3.
- What the Hell, Hero?: The entire team sandblasted him when he very coldly fired Paige, seemingly out of spite. In reality, it's because he had fallen in love with her but feared how it would affect their work relationship. Once the team learned this and he owned up to his cowardice and promptly struck his decision off the record, they were all too quick to forgive him.
Sylvester "Sly" Dodd
Played by: Ari Stidman
- Adorkable: Especially when someone gets him started on his favorite Super Hero, Super Fun Guy.
- Cannot Keep a Secret: In "Revenge", he immediately admits to Paige that he and his teammates were eavesdropping on her conversation with Drew.
- Challenge Gamer: In "Kill Screen", we learn that he was once a master gamer known as "El Guapo". He's still able to kill 30 dinosaurs in 10 seconds on a game that is apparently so difficult that the only requirement to get into a gaming convention's VIP section is being able to kill just 10 dinosaurs in a whole thirty seconds. And that is considered to be difficult to the point of disbelief by Toby, one of his fellow geniuses.
- Cutting the Knot: He can only do math if all the chalk on his blackboard is ordered according to length. Paige finds a way to skip this step: She only allows him one piece at a time (a list of one is always ordered).
- Dark and Troubled Past: Not too surprising given his overdeveloped EQ and the isolating effect of his high IQ. Sylvester was a constant disappointment to his military father (see Jock Dad, Nerd Son), who doesn't seem to have ever let Sylvester forget it. He was shipped off to live with relatives at a very young age (he hasn't spoken to his parents since he was 12, anyway), and that didn't work out so well either, because he ran away from them at 16. It's a good thing Walter found him soon after, because in "Revenge" he tells Megan straight out that he was right on the verge of doing "something stupid" (which some viewers have interpreted to mean Suicide).
- Sly's dad has since admitted that he always loved him but didn't know how to relate to him. Sly is still hesitant to reconcile with his mother.
- Face Your Fears: Sylvester has a lot of fears, and he has to face some of them from time to time in the course of working on a case.
- In "Single Point of Failure", he's forced to hide in a lab full of infectious disease samples, despite being Terrified of Germs. Walter later praises him for being courageous enough to do so.
- In "Dominoes", after a couple of screw-ups trying to rescue a boy trapped in a cave (see Nice Job Breaking It, Hero! below), he undergoes a 10-Minute Retirement. He explains to Megan that the boy's fate encompasses all his phobias, leaving him too emotionally distraught to maintain his focus. Megan responds with a Rousing Speech that motivates him to return and keep his fears under control.
- He hates water, and boats because they operate on water, but in "Love Boat" he has to board a cruise ship masquerading as a guest and later chooses to jump into the water to knock out the Villains of the Week who are escaping on a lifeboat.
- Faking the Dead: In "Fish Filet", he takes a combination of drugs that simulate death so he can escape from prison via the morgue.
- Geek Physiques: He's somewhere in the neighborhood of 250-300 pounds.
- Good with Numbers: Walter's opening monologue describes him as a human calculator.
- Happy Dance: He does one to celebrate a video game victory during an old clip in "Kill Screen". He regards it as an Old Shame.
- Jock Dad, Nerd Son: His father is a military hardass who's disappointed in him. In the pilot, he tells Paige he hasn't spoken to his parents in 10 years - and he's 22. In "Dominoes" he adds that his last Christmas at home (before he was shipped off to live with relatives) his Dad gave him a weight set for a present... just to repeat, Sylvester's Dad gave his eleven year old son a weight set! And the relatives didn't work out so well either - in "Revenge" he tells Megan that he ran away from home at 16. However, they finally accept each other when they work together in "Sun of a Gun".
- The Knights Who Say "Squee!": His reaction to going to the HQ of the company that writes Super Fun Guy is an epic example of this.
- Lovable Coward: Whenever the team heads into danger, he makes no effort to hide how scared he is, complaining and spouting scary statistics and factoids along the way. He's even talked about quitting.
- Neat Freak: Is highly germophobic and has OCD.
- Nerd Glasses: He wears them.
- Nice Job Breaking It, Hero!: In "Dominoes", he forgets to calculate the effect of the change in tides when figuring out how long the team has to rescue a boy who is trapped in a sinkhole. He blames his mistake on still being rattled from having been blown up during their last case ("Revenge"). He nearly quit the team because of this, believing the explosion had made him ineffective.
- Odd Friendship: With Megan.
- Parental Abandonment: His parents didn't know what to do with Sylvester so they shipped him off to his uncle.
- Photographic Memory: A trait he shares with Walter.
- Smart People Play Chess: Sylvester is a grandmaster... but Ralph is even better.
- Super Strength: Not to any obviously supernatural degree, but Sylvester is scarily strong when he wants to be. Examples include throwing (not planting) a chess piece into a concrete pillar hard enough for it to be used as a serviceable coat hook for six years , and preventing a large section of cliff from falling on an ECMO machine that is keeping a drowning boy alive. Perhaps he did use that weight set after all...
- Terrified of Germs: One of his quirks.
- Token Good Teammate: Averted in that none of them are bad guys, but he is the nicest member of the original team, due to his having a higher EQ than average, rather than lower than average.
- Took a Level in Badass: After the Faking the Dead incident in "Fish Filet", his recovery leaves him feeling brave enough to not only complete the mission before escaping, but save himself when a gang leader he'd antagonized attacks him ("I have a limit of one death per day"). And then he finally tells Megan that he loves her!
Happy Quinn Curtis
Played by: Jadyn Wong
- Asian and Nerdy/Brainy Brunette: She's both of these, but atypically for these tropes, she's also a Tank-Top Tomboy.
- Awesomeness by Analysis: How she became a pop-idol in South America. She carefully analyzed trends to make the most souless-yet-catchy music she could. It was a complete success and she's completely ashamed of it. But she really needed the money.
- Belligerent Sexual Tension: With Toby. The sexual tension is resolved by "Fractured", though the belligerence is not.
- Catchphrase: "Not good!", her version of Oh, Crap!.
- Citizenship Marriage: She faked a marriage with Walter so that he wouldn't get deported back to Ireland. The two kept this an ironclad secret considering Toby's predictable response, but it proved no good in the long run when Toby learned this through a cryptic clue from disgraced teammate Mark and he went absolutely berserk. Then an agent started in on them when she could tell the marriage was phony. However, Walter landed his citizenship and both he and Happily promptly broke off the "marriage".
- Deadpan Snarker: She has her moments, especially when dealing with Toby. As in, "most of her life".
- Disappeared Dad: He abandoned her as a child. This was not because he didn't want to raise her himself but because after her mother's death giving birth to her, he became an alcoholic and he realized that he couldn't raise her right.
- She tracked him down and started helping out in his garage. When she almost gets up the courage to tell him who she really is, she changes her mind at the last second. But he tells her that he has known since he first saw her walk in to his garage.
- The Engineer: A mechanical engineering beast.
- Expansion Pack Past: Admits to bouncing around a lot and doing whatever came her way, including ice road trucking, recording a single (in Portuguese no less), and working on the set of Prince of Persia: The Sands of Time with Jake Gyllenhaal.
- Happily Married: She tied the knot with Toby in Season 3, but the marriage got off to a really rocky start thanks to missing the intended wedding ceremony and having to do an impromptu backlot ceremony, then a plane crash mid-honeymoon.
- Hot-Blooded: Her first reaction to someone being a jerk tends to be violent.
- I Don't Want to Ruin Our Friendship: In "Love Boat", she tells Toby that yes, she does like him the way he likes her, but she's never been best friends with someone before like she is with him and doesn't want to jeopardize that by getting romantically involved.
- Impersonating an Officer: In "Rogue Element", she borrows Cabe's ID and uses it to gain access to a crime scene by posing as a Homeland Security agent.
- It Is Pronounced "Tro-PAY": When the cop on duty asks her what kind of name Cabe is, Happy claims that it's pronounced "Kah-Be" and that it's Korean.
- Interchangeable Asian Cultures: In addition to passing as as Korean, Toby passes her as the Japanese "Zuki Fujimoto" in 2x01 "Satellite of Love". It seems that this will fail when the Russian desk clerk turns out to speak Japanese. As it turns out, so does Happy. Jadyn Wong is Canadian of Hongkonger parents, meaning southern Chinese.
- Ironic Name: More than a little cranky for someone named "Happy."
- Jerk with a Heart of Gold: She's ill tempered and deliberately offputting, but she's the one who dragged Walter out of the rabbit hole he'd jumped into even though it took her a week to do it.
- Missing Mom: Her mom died in childbirth, and her demise spurred her dad into giving her up for adoption because he couldn't raise her on his own. However, he held onto some home videos that allowed Happy to see what she looked like in life prior to her birth, in a tape made where her mother spoke to Happy by welcoming her into the world.
- Mixed Ancestry: Her father is white.
- The Reveal: She married Walter to validate his citizenship.
- Tomboy and Girly Girl: The Tomboy to Paige's Girly Girl.
- Twofer Token Minority: She's female and an Asian-American who's is the only clearly non-white member of the core cast.
- Tsundere: Despite her love for Toby, she can be a little hostile and even intimidating towards him.
- Wrench Wench: She's a "mechanical prodigy".
Tobias "Toby" Curtis
Played by: Eddie Kaye Thomas
- Awesomeness by Analysis: They all do this to a certain extent but he's the master of it.
- Belligerent Sexual Tension: With Happy. The sexual tension is resolved by "Fractured", though the belligerence is not.
- Deadpan Snarker: There's rarely a moment when he isn't snarking.
- The Gambling Addict: The first time we see him he's running from some people who thought he was cheating at cards. He wasn't; his Awesomeness by Analysis just makes him very good at reading tells. This becomes a serious problem when the team goes to Las Vegas in "Shorthanded". After he gets together with Happy, he eventually gives up gambling when he sees how much it scares her in "The Fast and the Nerdiest", and has seemingly been clean ever since.
- Happily Married: He and Happy tie the knot in the tail end of Season 3. The honeymoon gets a bit bumpy when the team crashes on a deserted island, but the team is rescued in the season finale, with Happy and Toby happily together.
- Ivy League for Everyone: He went to Harvard.
- Meatgrinder Surgery:
- In "Kill Screen", he resorts to this to keep a stabbing victim alive until he and Happy can reach a hospital, including using Happy's tampons to stop the bleeding and her jumper cables to restart the patient's stopped heart. It works.
- In "Ice-ca-Cabes", he performs emergency surgery on Cabe, which includes lowering his core body temperature, letting a rattlesnake bite him to provide blood thinning, and electrocuting him to restart his heart. It works.
- Nice Hat/Never Bareheaded: He's rarely seen without his porkpie hat. In fact he stalled the team from leaving just so he could grab his hat before they headed out.
- He eventually loses it when he falls down a cliff on a top-secret mission in Bosnia. He complains bitterly about it for a few episodes before the Christmas episode, when Happy gives him either a very similar replacement hat, or the original.
- Nice Job Breaking It, Hero!: He's done this at least three times.
- In the pilot, Happy and Toby retrieve a Magic Floppy Disk (specifically a server) that can replace LAX's defective software... but on the car ride home, Toby puts it next to a radio speaker and the magnet therein, rendering it useless.
- In "Shorthanded", the team has made half of what they need to pay to get Walter out of jail. On a gambling high, Toby bets it all on roulette and loses everything, leaving Walter stranded in jail.
- In "Father's Day", Toby sends Cabe and his soldiers to the wrong location after misreading a Morse Code signal. Fortunately, Cabe's team realize their mistake, leading to a Big Damn Heroes moment.
- Photographic Memory: Toby remembers everything he studied from his medical training at Harvard, which allows him to speak with authority on medical issues despite being a psychiatrist.
- "The Reason You Suck" Speech: He receives one in "The Old College Try" from Quincy Berkstead, his college nemesis, whom Toby thinks stole his fiancee Amy. Quincy calls Toby "an egomaniac and a narcissist" who can't admit that he drove Amy away with his gambling addiction. Toby later admits that Quincy was right.
Played by: Katharine McPhee
- Good Parent: She may not fully understand Ralph, but she clearly loves him and bonds with him as best she can. Also, she's very grateful when Walter and his team help the two of them connect. However, she almost leaves the team when she sees Ralph imitating Walter's dangerous behavior, but eventually realizes that they all need each other.
- The Heart: She's on the team to serve as the face, being the person that a client can talk to who will actually be able to empathize with normal people. In fact, Cabe calls her "the glue holding this team together".
- Relationship Upgrade: She and Walter eventually worked out their differences and got together right after Toby and Happy tied the knot, much to the delight of everyone else, especially Ralph, who wanted this outcome all along.
- Romantic False Lead: The soldier who was introduced to the team to help protect them hitched up with Paige despite Ralph's dislike of him and Walter's utter disdain. Unfortunately, Walter seemed bent on getting rid of him by ejecting him from the team very scornfully. Paige was understandably furious, and it ultimately led to the collapse of the relationship...for a while.
- Only Sane Employee: She's usually the socially capable member of Walter's group. Lampshaded when she is first hired by Walter, to "translate" himself and his friends to the non-genius world. They help her understand Ralph.
- She Cleans Up Nicely: In "True Colors". Walter is all but speechless.
- Tomboy and Girly Girl: The Girly Girl to Happy's Tomboy.
Special Agent Cabe Gallo
Played by: Robert Patrick
- Badass Grandpa: While he is this trope through and through, Cabe is actually scared of getting older, not because he's afraid to die, but because he fears he'll be too weak to save the people he cares about.
- Badass in a Nice Suit: He's always in a suit and tie.
- Badass in Charge: He's technically in command of Walter's team. Whether he's actually able to control them is another matter.
- Broken Pedestal: When the series first starts, Walter blames him for the Baghdad bombing. The relationship is slowly getting better, at least until...
- Dark Secret: In "Once Bitten, Twice Die" it's revealed that the Broken Pedestal incident was actually even worse than Walter thinks it is. The head of DHS believes that Walter would consider it a Moral Event Horizon. In "Cliffhanger", it's revealed that Cabe was informed about the bombing run three days in advance, but did not tell Walter because he knew Walter would sabotage the software - which Water confirms, not for any anti-war reasons, but simply because the software wasn't meant for that and would kill everything in sight. The government decided they knew how to use the tool better than the guy who built it, Cabe didn't correct that idiotic assumption, and that is why 2000 people died.
- FBI Agent: He was with the FBI when he arrested Walter, though he's transferred to Homeland Security in the years since.
- Heartbroken Badass/Outliving One's Offspring: His daughter died very young, which led to the breakup of his marriage.
- Amicable Exes: However, he gets along with his ex-wife, and enlists the team to help rescue her when she's kidnapped.
- Parental Substitute: To Walter, who has a distant relationship at best with his father, but was grateful to Cabe for keeping out of prison after his NASA hack. At least until the Broken Pedestal thing. He eventually becomes one to the whole team.
- Playing Gertrude / Hollywood Old: Slightly. In s03e17, Cabe mentions that he likes getting senior discounts. Those generally start at 60, and when that episode airednote , Robert Patrick was 58.
- "It's Raining Men (Of War)" (4x09) is set on Thanksgiving 2017, and says Cabe is 59. That's Patrick's actual age for that date, which would mean the writers forgot, the earlier remark was a joke, or Cabe somehow adds a few years to his age to get senior discounts.
- Reasonable Authority Figure: Despite their Dark and Troubled Past together, Cabe reaches out to Walter because he really cares about him. He's openly acknowledged as Walter's father figure and despite their contentious past, it's a relationship they've resumed. Cabe is very supportive towards the rest of the team as well, praising and defending them whenever his colleagues criticize them.
- Shipper on Deck: Very much in favor of pairing Walter and Paige together. When they finally reciprocated each other's feelings and the team caught them nomming each others' faces in a supply closet, his response was, "Well, it's about damn time!"
- Team Dad: Openly acknowledged.
Played by: Riley B. Smith
- Batman Gambit: In "Fish Filet", a bully forces Ralph to do his homework for him. Paige rules out running away or fighting back. What should he do? He applies to several prestigious universities, including Caltech and Harvard, and is actually accepted by all of them. This gets him on the news—All According to Plan, since he knows that his classmates won't pick on a celebrity. He's even wise enough to stay at his school so he'll grow up better adjusted than Walter and company.
- Child Prodigy: He's only nine at the start of the show, but he knows more about physics than many adults. And then there's his chess and video game skills...
- Deadpan Snarker: By default, any snark from him (assuming it is snark) is deadpan. Like the time he and his con-artist grandma turn regular brownies into organic cruelty-free brownies to sell to trendy folks. Afterwards, he mentions that he didn't really need that much help to "fleece hipsters".
- Disappeared Dad: His dad left the family when Ralph was little, but Drew has since attempted to reconnect with him.
- Intelligence Equals Isolation: He has trouble relating to his schoolmates. Fortunately, Team Scorpion are happy to befriend him, because they can relate to his lack of social skills.
- Intergenerational Friendship: With the rest of Team Scorpion, particularly Walter and Sylvester.
- No Good Deed Goes Unpunished: In "Cliffhanger", Ralph cons his way out of school, past a police blockade and into a building about to release a massive amount of Sarin gas and proceeds to save everyone in the city by sealing a hole in the building. As a result, Paige almost takes him cross-country to be with the father who abandoned him because all she sees is her son risking his life just like Walter does.
- Nom de Mom: Ralph has his mother's last name instead of his father, Drew Baker.
- Shipper on Deck: He wants Walter to get together with Paige, both because he wants Walter as a father and because he thinks Walter is good enough for Paige. When Walter fires Paige because he was too scared to admit that he was in love with her, it's a huge Broken Pedestal moment for Ralph, telling Walter that if he weren't a kid, Ralph would beat up Walter for hurting his mother. He forgives Walter when he apologizes and Paige and Walter get together.
- Smart People Play Chess: Sylvester is a grandmaster. The team realized that Ralph is a budding genius when he beats Sylvester; by the time Paige is alerted to what's going on, Ralph has Sylvester in checkmate in eight moves. Using sugar packets on a non-checkerboard counter top.
Megan O'Brien Dodd
Played by: Camille Guaty
- Ambiguously Brown: Same as Walter.
- Black Comedy: Megan uses this to help herself and others cope with her condition.
- Beta Couple: With Sylvester. They get together and stay in a relationship, culminating in their marriage before she dies.
- Cool Big Sis: Walter claims that Megan was the only one in his family who was able to connect with him.
- Ill Girl: Megan has Multiple Sclerosis and is in the hospital full time for assisted living.
- Killed Off for Real: Her MS worsens during the second season, and she finally succumbs to it in "Arrivals and Departures".
- Odd Friendship: With Sylvester.
- Sibling Yin-Yang: Megan is playful and empathetic while Walter is more antisocial and analytical.
Played by: Joshua Leonard
- Arc Villain: Of the Season 2 finale, kidnapping Toby to prove that he is ultimately smarter than the rest of Scorpion. In the Season 4 opener, he tricks Cabe into letting him escape custody, which gets Cabe suspended as a federal agent pending a trial. This hangs over the rest of the season.
- Conspiracy Theorist
- Does This Remind You of Anything?: His friendship with Walter involved him showing up and taking Walter on "brain binges" where they'd try to solve cancer and forget things like eating, or bathing, or the rest of the universe. It's treated exactly like he's an abusive drug addict ex-boyfriend who keeps pulling recovering addict Walter back in and trying to alienate him from his friends, except the drug is intellectualism.
- Evil Counterpart: Walter seems to see him as not only this, but what Walter himself might have become, which is why he still has some compassion for his former friend.
- Insufferable Genius: He stands out in a series full of them. He's so manipulative and condescending that Walter is the only one of his old teammates who can tolerate him.Collins: Did you get smarter, Sylvester?
- Manipulative Bastard: Does everything in his power to divide the team.
- Poisonous Friend: To Walter. Their interacting with each other and brainstorming ideas was done to the expense of everybody else around them (it didn't help that Collins was an even bigger Insufferable Genius to the team and only respected Walter), and it got so bad that Walter had to put him in an asylum. When the team needs to race to fix a nuclear reactor (with only the information Collins has obtained from years of listening to the plant's electronic traffic to help them), Collins is quick to try to put Walter on his side and sabotages the team's efforts.
- Smart People Play Chess: But not so much because he's good at playing the game but because he's good at mind games and forcing his opponent into playing badly.
- Stalker with a Crush: He sets up a nuclear meltdown to draw in Walter. Pretty much every exchange with Walter has either a jilted lover vibe or this. It's damn creepy.
- Teeth-Clenched Teamwork: When Scorpion is forced to rely on his services at the start of Season 4, Mark tries to pretend they are all still buddy-buddy but nobody wants to even acknowledge the cretinous air he breathes.
- Token Evil Teammate: But he was so crazy that they had him committed.
- We Used to Be Friends: His relationship with most of the team. However, Walter still has some residual pity for him, which winds up endangering the mission.
- Wounded Gazelle Gambit: Tricked Cabe into releasing a proximity breach-activated shock collar that would keep Mark from wandering too far away from Cabe when his services were necessary in the Season 4 two-part opener. Cabe needed to do something that would force them to be split up too far and cause Mark to agonize from relentless shocks and incapacitate him rather cruelly. But being the weasel he is, Mark took the first opportunity to bail out and flee, leading to Cabe getting into deep trouble.
Played by: Keven Weisman
- Cloudcuckoolander: Walter, Happy, Sylvester, and Toby are odd. Ray is a whole different level of strange, legitimately believing that San Jose, California is a myth.
- Hidden Depths: He might be a scatterbrain, but Ray isn't especially dumb; he knows Polish well enough to serve as a translator good enough to fool the U.N. Even if he does confuse 'matter' with 'platter'.
- Honorary True Companion: He's not a genius or a member of Team Scorpion, but he's a friend of Walter, and has helped them on a few important occasions that saved their lives, as well as marrying not only Sylvester and Megan, but later Toby and Happy.
- My Greatest Failure: He was a firefighter who had a close friendship with fellow firefighter Danny Tuggle, getting so close he was named godfather of Danny's son. However, they got hit with smoke in one fight, while Danny put Ray's respirator on, Ray was unable to get Danny's respirator on in time to save Danny. It traumatized him so much that he basically became a drifter living out his car for ten years. Walter proving that the tank was defective is a huge weight lifted off his shoulders.
- Odd Friendship: With Walter, the logical, unemotional genius, while Ray is an emotional and... weird guy.
- Running Gag: He can never remember Paige's name, calling her various other names that start with "P".