NOTE: This spoiler was submitted by Jeremy.
Billy McMahon (Vince Vaughn) and Nick Campbell (Owen Wilson) are in a car playin Alanis Morissette's "Ironic". Nick complains that this is on the "get psyched" playlist, but Billy assures him he's got reason to by psyched. They meet with a hopeful customer named Bob over dinner, where they successfully charm the pants off him. When Nick presents their product, a watch called the ChronoShock 2013, Bob unceremoniously informs the duo that their company has closed.
The guys meet with their boss Sam (John Goodman). According to him, watches are obsolete and nobody has need for them since they can check the time on their phones. He sends the two out. As they get in the car, "Ironic" plays again, but Nick stops Billy from turning it off, as it is now fitting.
Billy's girlfriend Megan (Joanna Garcia) is moving out and dumps him because he has failed her too many times. At night, as he looks for another job, he goes to Google's main page and hatches an idea.
Nick takes a job working for his sister's lecherous boyfriend Kevin (Will Ferrell), who goes to make a pass at a customer. While Nick takes care of another customer, Billy comes in and tells him that he scored an interview for an internship with Google. Nick isn't completely on board, but after having had enough of Kevin's obnoxious behavior, he quits and follows Billy out.
In order to be qualified for the internship, Billy enrolls him and Nick at the University of Phoenix. The guys go to the library and have a video chat with the interviewers from Google. They ask the guys a weird question about what would they do if they were shrunken down and put at the bottom of a blender. After a series of odd answers, Nick fesses up and says they picked themselves out of the metaphorical blender and got themselves before them, which ought to be enough.
In a meeting of Google executives, a man named Mr. Chetty (Aasif Mandvi) asks the other Google employees of their assessment of Billy and Nick's interview. The majority seems dismissive, but one guy named Lyle (Josh Brener), sticks up for the duo based on their experience in sales and overall years of knowledge.
The guys are flown out to the Google headquarters in California and they are both astonished by how cool the places appears. They gather with the other interns and meet Graham (Max Minghella), a smug and douchey intern who ditches them after learning they are interns. Their first impression doesn't go over well during a test of their knowledge on rules in the workplace after answering several questions improperly, and Chetty already has doubts over them.
The next day, everybody gathers to be placed in teams. Graham assembles his own team quickly, while Billy and Nick are ignored. Lyle gathers them and three other rejects - Stuart (Dylan O'Brien), Yo-Yo (Tobit Raphael), and Neha (Tiya Sircar). They do not get along as Stuart is too sarcastic, Yo-Yo is too timid, Neha talks too much, and Lyle tries too hard to relate to them.
During a lecture on Google translator, Lyle checks on a dance teacher named Marielena (Jessica Szohr), which inspires Nick to go after Dana (Rose Byrne), an executive. She isn't impressed with Nick's attempts to flirt, so he tries to appeal to her as a colleague. He gets pulled away by another executive, Sid (Eric Andre), who has him meet his team.
Chetty challenges the team to find the bug in a code. While Billy and Nick try their own fast-talking way to get to the bug, the others work on their own, trying to best each other. When they feel the guys are slowing them down, they trick them into going to Stanford to find a guy in a wheelchair and calling him Professor Xavier. The guys find this sort of man, but since he thinks they're mocking him, he punches both of them and rolls out. The guys go back to HQ where Graham brags about his team finding the bug and then says he'll be winning the sports challenge.
The sport in question happens to be Quidditch. Team Lyle, as they refer themselves, trails behind Graham's team, but through some motivation from Billy via references to "Flashdance", he inspires the others to work together. However, they still lose the match.
The next challenge is to make a new app. The team can't figure anything out because they keep arguing. Billy proposes an idea where photos are taken and can be exchanged via a social network, unaware that he is describing Instagram, even as the others call him out on it. The team appears to want to quit, showing their cynicism over the real world, which prompts Billy and Nick to take them all out on the town.
The team goes to a bar. Nick gets Stuart to look up from his phone (he's always texting) to go talk to a sexy waitress, while Yo-Yo gets crazy drunk after being so wound up. Lyle even finds Marielena and gathers the courage to buy her a drink. They're all having a good time until a jerk comes in to mock the team. A brawl ensues between Billy, Nick, the jerk, and his friends. They still come out proud.
As the sun rises near the river, Stuart admits that he had the best night of his life. Neha, meanwhile, laments to Billy over not having a boyfriend, but Billy assures her she'll get there someday. Lyle almost drunk texts Marielena a picture of his penis while the others stop him with math questions. This inspires the idea to make an app on preventing drunk texts. Chetty later congratulates the team on the app being the most downloaded.
Nick finally decides to ask Dana out even after she earlier felt tired of being disappointed by asshole guys. Even so, she agrees to the date. Elsewhere, Billy is in the sauna where Graham is also. He gets in Billy's head and tells him he will end up failing himself yet again.
The next challenge is to man the helpline. Billy is at HQ studying. He encounters a quiet Google employee known as Headphones (Josh Gad), due to him always wearing headphones. The guy is pleased with Billy's kindness toward him and he helps him out. Meanwhile, Nick goes on his date with Dana, jokingly playing off as an asshole by flirting with the waitress, but still managing to charm Dana. She allows him to spend the night with her.
The time for the helpline challenge comes up. The team is killing it, especially Billy, but because he forgot to log in, his work is not recorded and his team does not get to pass. Billy is discouraged and feels he has failed the team. He quits the internship and goes to work for a guy named Randy (Rob Riggle), who has him sell carts to retired folks.
The final challenge is a sales challenge. Nick goes to find Billy to convince him to come back for this since he's a great salesman. Meanwhile, the team tries to make a sale to a pizzeria owner for him to expand his business, but they aren't doing so well. In comes Billy and Nick, who charm the man and eventually appeal to him with facts presented on the internet and finally get him to expand.
The time comes for Chetty to announce the team who gets the job. Team Lyle isn't back, so Chetty almost disqualifies them for not handing in their sale, but the system is hacked to show off a goofy music video of the team dancing, just as they come in with boxes of pizza from the pizzeria. They also hand Chetty their sale. Graham tries to butt in and say they can't get the job because their sale wasn't enough to earn them the proper points, which Chetty agrees with. However, since they helped the restaurant expand into what might be a profitable business, they did a better job than what was expected of them. Graham dismisses this and asks if somebody important can come make a decision. In comes Headphones (real name Andrew), who says that Billy and Nick helped the team work together and strive for accomplishment, while also trashing Graham. With that, Chetty finally turns to Team Lyle and utters the words "Welcome to Google". The other interns cheer Team Lyle on as Graham goes to complain and insult his team. This earns him a punch to the gut from a team member he'd been berating the whole time. Nick goes over to kiss Dana in triumph.
The team departs for the summer, with Yo-Yo standing up to his mom after she's been stressing him out for success, Lyle now in a relationship with Marielena, and Stuart and Neha hinting they may get together. Billy and Nick walk off campus together, hopeful for what the summer will bring.