Leonard returns home to find Sheldon hyperventilating in anxiety. A police officer is present, trying to calm Sheldon down, after having been sent when Sheldon called the Pasadena Police Department in a panic. Although Sheldon seems to be speaking of actual items, it becomes clear to Leonard that what had actually happened was that Sheldon's World of Warcraft account was hacked. Sheldon called the FBI (who, he says, had hung up on him) and then the local police. With another individual now present, the officer leaves, derisively telling Sheldon that the police do not have jurisdiction in Pandora (Sheldon corrects him by stating the setting for World of Warcraft is, in fact, Azeroth). Rather than reporting the incident to the game's developer, Blizzard Entertainment Sheldon assembles the guys to track down the offending hacker.
Later, Penny brings Sheldon a cheesecake, hoping to console him. Penny encounters Priya as she's departing Leonard and Sheldon's apartment. Penny nervously explains the situation to Priya—in part, ostensibly, to assuage the latter's earlier request that Penny dissociate herself with Leonard. This action confounds Priya—and she becomes even more irritated when Priya determines that Leonard is working with Howard and Raj in order to find the culpable hacker. Eventually, Priya decides to leave, intoning a sarcasm|sarcastic comment that whizzes by Leonard and causes Sheldon to realize a very rare, unspoken bazinga.
Meanwhile, Penny is hosting Amy and Bernadette at her apartment. There, they discuss Priya. Penny is furious that Priya is benefiting from all of Penny's efforts to encourage Leonard to be more adventurous and willing to try various things. Her thanks, she says, is that she is now denied the right to talk with Leonard anymore. Bernadette suggests that they socially reject Priya. Amy responds that it is the natural response of members of a primate sociality|primate social group to want to throw their feces at individuals who disturb the social group. Penny denies that it has gone that far. As they depart to go drinking, they encounter Priya as she is leaving Leonard and Sheldon's. Amy actively displays her hostility towards Priya, as the four women walk down to the lobby.
The following day, Howard tells the group that he has determined the identity of the offending hacker and has determined the hacker resides within a short driving distance, Carlsbad just north of San Diego. Sheldon persuades the others that they should drive to the hacker-thief's house that evening and confront him as to the acts they believe him culpable of. Leonard interposes his reservations as to this course of action, as he doesn't feel it appropriate to stand Priya up for two straight nights.
Prior to departing, it develops that Leonard had told Priya he had been working late to explain his absence and to "cover" his involvement in the group's activities. The news of Leonard's deception of Priya upsets her brother Raj who is incensed further when asked by Leonard to "cover him" when Priya asks Raj whether Leonard was telling the truth—although Raj acts in a brotherly way, in order to get the point across to Leonard.
The gang then proceeds to the hacker's residence to confront him, only to discover that he is a taller, bigger teenage nerd. When Sheldon asks for his property to be returned to him, not only does the hacker refuse, but he also takes Sheldon's collectible Klingon bat'leth which Sheldon brought along as a form of intimidation and immediately shuts his door. Defeated, the gang proceeds to return home. On the way, Leonard's breakdown car breaks down. They call Penny to take them home in her car. Penny is surprised Leonard did not call Priya to explain his absence. Leonard indicates it was because he had told Priya he was working, and Penny notes that this time might mean that on that occasion, Leonard perhaps did not want to see Priya. Reacting Penny only says "interesting". Penny discovers the gang has failed in their quest. At becoming aware of this development, Penny immediately takes the gang back to the hacker-thief's house, vowing to show them how to solve a quest "Nebraska-style". When the hacker denies his actions to Penny, she responds by delivering a groin kick to the hacker and persuades him to return Sheldon's World of Warcraft objects and account settings to the way they were.
The following day, Penny encounters Priya in the lobby, and the two walk up the stairs together in strained silence. After Priya enters Leonard's apartment, Penny, realizing to herself she has become "territorial" about the guys, comments to herself that Amy was correct, and says that "I do want to throw poop at her".
- Guest starring:
- Teleplay: Bill Prady, Dave Goetsch & Jim Reynolds
- Story: Chuck Lorre, Steven Molaro & Maria Ferrari
- The TV Critic: "For once Sheldon wasn't a pest, annoying everyone with his selfish needs. Instead he was an innocent victim and all his friends rallied around him to make sure justice was done. Sheldon finally got to play the most likable role I can imagine for him as he rallies the geeks against the bully|bullies of the world... I felt this tone extended to Penny too. She stood in understandable contrast to Priya in being instantly sympathetic to Sheldon for his loss... One of the things I love about sitcoms is the shameless escapism of just cheering on goofy things. It's been frustrating to see The Big Bang Theory use so much irritation and argument in their stories when co-operation can be this much fun. With the expansion of the cast and a bit of growth from Sheldon it feels like the show is slowly embracing this a little more warmly. Its encouraging news and I hope for more of it."
- The A.V. Club gave this episode a B-.
- IMDb user reviews
- Title Reference: Todd Zarnecki makes an incursion by hacking into Sheldon's World of Warcraft account.
- Chuck Lorre's vanity card.
- This episode was watched by 11.92 million people with a rating of 3.7 (adults 18-49).
- This episode aired in Canada on March 31, 2011 with 3.216 million viewers and a weekly ranking of #1.
- In the United Kingdom, this episode aired on August 11, 2011 with 1.431 million total viewers and a weekly ranking of #18.
- Episode transcript 
- Sheldon sports his ManBot t-shirt, arguably his favorite as it is the one he has worn in more episodes than any other - and in more colors (green, blue, and purple). He also wears the red "Robot Evolution" t-shirt.
- The first appearance of the living room in Mrs. Wolowitz's house; it doesn't appear again until "The Thanksgiving Decoupling" (S7E9).
- Sheldon's level 85 Blood Elf has a "Battle Ostrich" named Glenn.
- Sheldon's Blood Elf has increased by 5 levels since he mentioned it was level 80 in "The Apology Insufficiency" (12 episodes ago in S4E7). This follows World of Warcraft's increased level cap between the two episodes.
- Bernadette and Amy only feature in two scenes with Penny in this episode gathered as Penny's Posse.
- 1. The scene where they both get bowls of ice cream with coffee liquor served by Penny at the table in her apartment whilst talking to Penny about beaches, etc.
- 2. The scene where they meet Priya in the hallway to have a small chat before they go down the stairs to which Amy says 'Four women walk down the stairs. How many reach the lobby?'.
- Howard's mother has an 'uncanny' (Sheldon's description) knack for solving Wheel of Fortune puzzles. Howard mentions that, along with jiggling her arm fat, it's her Superpower (ability)|superpower.
- Raj likes Beyoncé's music (and her curves), and had a Scooby-Doo Trapper Keeper.
- The choice to play the "Ride of the Valkyries" song while driving to Carlsbad, California|Carlsbad shows their lack of understanding of the Caltech undergraduate culture. At Caltech, that is a song that is shunned as it is often used as a wake-up call during finals.
- Penny shows the guys how they complete a quest in Nebraska, involving a tactical groin-kick. Another time she plans to go all Nebraska if there is an intruder and then she picks up a baseball bat.
- Many inconsistencies involving the actual game of World of Warcraft, but Sheldon makes unintended puns that involve terms.
- Amy and Bernadette share no scenes with the men (Howard, Sheldon, Leonard and Raj) in this episode.
- Many of the things stated in the episode aren't in this episode or possible in the actual World of Warcraft game. The only thing possible to be taken from Sheldon's account listed by him is the gold. The weapons, and armor stolen from Sheldon could have been disenchanted (broken down into magical components), or sold to a merchant to get gold, but not sent to another character as they'd be soul bound (stuck to that character). The ostrich mount Glenn could not have been stolen as mounts have been learned skills for quite some time. Howard suggested Raj stop dropping his sword and bending down to pick it up. It is not possible to drop your weapon onto the ground, and there is no emote to bend over.
- The Pasadena Police Department has no authority in the "World of Warcraft" local of Azeroth.
- When the gang is in Leonard's car, Sheldon says "Sea World is better. It has Shamu, who is literally tons of fun." This goof made by the scriptwriters, because it is a misuse of the word 'literally' ('fun' cannot literally be weighed), which Sheldon would never do, and in previous programs he made fun of Penny's dim boyfriend, Zack, for doing it.
- Items Sheldon had stolen: enchanted weapons, vicious gladiator armor, wand of untainted power, all his gold and his battle ostrich named Glenn - the only bird he ever loved (in Todd's initial hack of Sheldon's account), and the bat'leth (taken by Todd when Sheldon and the gang first went to confront him).
- Penny: Did you know last weekend Priya took Leonard rollerblading at the beach? Can you believe that?
- Bernadette: I feel like I’m supposed to say that bitch, but I don’t have enough information.
- Penny: I am the one who spent two years trying to get him to even go to the beach in the first place. And he was so phobic about stepping on medical waste, I had to carry him to the water.
- Bernadette: (sarcastic) I took Howard to the beach once. He almost burst into flames like a vampire.
- Penny: So what’s the thanks I get for turning Leonard into quality boyfriend material? I have to tiptoe around his new girlfriend.
- Amy: I think you’re on.
- Bernadette: (she's quite guiltily) Oh. (she gasps crossly) That bitch!
- Penny: Want some coffee liqueur on your ice cream?
- Amy: Ah, here’s the alcohol and drug peer pressure Mother warned me about. I was starting to think it was never going to happen. Yes, please.
- Penny: You guys should’ve seen Leonard when I first met him. There was no eye contact. He was either looking up at the ceiling, or down at his shoes.
- Amy: I’m drunk.
- Penny: You know, for the first couple of months, whenever I would take off my bra, he would giggle and say, oh boy, my breast friends.
- Bernadette: Well, if it makes you feel any better, I’m never speaking to Priya again.
- Penny: No, don’t do that. No reason to be mean to her.
- Amy: This may be the alcohol talking, but I believe there is. Are you familiar with the recent study of Tanzanian chimpanzees by Nishida and Hosaka out of Kyoto University?
- Penny: No, but I can name all the Kardashians.
- Amy: Primates, such as ourselves, have a natural instinct to ostracize ill-mannered members of the troop. Bernadette’s urge to shun, scowl or fling her waste at Priya is hard-wired into her DNA.
- Bernadette: (she speaks to Amy crossly) I don’t have an urge to fling my waste.
- Amy: Believe me, it’s there, we all have it. Hit me with some more booze, and I’ll show you.
- Sheldon: Stale pastry is hollow succor to a man who is bereft of ostrich.
- Penny: Just say thank you.
- Sheldon: I thought I just did.
- Sheldon: Why hast thou forsaken me, o deity whose existence I doubt?
- Penny: Oh, hi! I was just dropping a cheesecake to Sheldon. He was robbed of a bunch of imaginary crap that's useful in a make-believe place.
- Priya: I don't know what that means.
- Penny: Yeah, well, sadly, I do!
- Amy: Well, well, well. Look who it is.
- Penny: Okay, be nice.
- Priya: Hello.
- Penny: Hi. We’re just heading out for a drink.
- Amy: Because I do that now.
- Bernadette: Count your blessings you’re not a Tanzanian chimp.
- Priya: What?
- Penny: Don’t listen to her, she’s had a lot of ice cream. Do you want to join us?
- Priya: Oh, thank you, but I have work to do.
- Amy: Four women walk down the stairs, how many reach the lobby?
- Leonard: I don't know if I can ditch Priya two nights in a row.
- Raj: Oh, come on, man! Bros before... my sister.
- Todd Zarnecki: Now what?
- Penny: Give my friend his stuff back.
- Todd Zarnecki (denying any wrongdoing): I don't know what you're talking about.
- Penny: Well then, good news! Today's the day a girl's finally going to touch you in your little special place. (kicks him in the groin) Now give him his stuff back.
- Todd Zarnecki (on his knees in clear pain): Okay.
- Sheldon: We did it! (the gang looks at him, unconvinced) I said we.
- Penny: (after she and Priya walk up the stairs in a tense silence) Amy is right. I do wanna fling my poop at her!
- Penny: So, Leonard, I think it's interesting you didn't call your girlfriend to come get you.
- Leonard: Oh, I kind of told her I was working.
- Penny: Oh. So you lied to her. Also interesting.
- Leonard: She doesn't really understand the whole World of Warcraft adventure role-playing thing.
- Penny: Oh. Doesn't matter if she gets it, as long as she's pretty.
- The Big Bang Theory - The Zarnecki Incursion (TV Episode 2011) - IMDb
- The TV Critic's Review
- The Big Bang Theory: "The Zarnecki Equation" - TV Club - The A.V. Club
- Thursday Final Ratings: 'American Idol,' 'Big Bang Theory,' 'Rules Of Engagement,' 'CSI,' 'Grey's Anatomy' Adjusted Up - Zap2it
- Top Programs – Total Canada (English) March 28 – April 3, 2011 - BBM Canada
- BARB via Wikipedia