When Ted pulls an all-nighter working on a pitch in an attempt to bring business to his fledgling architecture firm, Marshall tries to lure him to the roof for a surprise 31st birthday party.

In his attempt to assuage his guilt for "ruining Ted's life," Tony, Stella's fiancé, insists on helping Ted find a job, but only manages to prove that no good deed goes unpunished. Meanwhile, Barney tries to prove he can get out of a speeding ticket.

After Ted runs into an old flame, he talks to his future kids about how being in the right place at the right time can impact a person's life. Meanwhile, Barney celebrates his 200th female conquest.

When Ted breaks Barney and Marshall's "three days rule" by having a "text" relationship with a girl he just met, they play a cruel joke on him by pretending to be her.

When Ted loses his job and decides to form his own architectural firm out of his apartment, he hires an intern to help get his company off the ground, but the intern gets too close for comfort with some of Ted's friends.

When Barney hears that Ted has made a list of things he feels the gang is too old to do, he attempts to complete every task on the list within 24 hours to prove Ted wrong.

When Goliath National Bank cancels plans to build their new headquarters that Ted was hired to design, Barney and Marshall concoct an elaborate lie to keep Ted from knowing he is out of a job.

When Karen finds another woman's earring in Ted's bed, he discovers that Lily planted it there on purpose, and that she secretly meddled in some of his previous relationships as well.

When Lily and Marshall hear that Ted's college girlfriend, Karen, has moved to New York City, they finally reveal how much they hated her back then.

When the gang suspects that Barney has a girlfriend after he mysteriously leaves MacLaren's, they decide to follow him.

When Robin realizes that she only has four days to get a job or she will be deported back to Canada, she agrees to let Barney produce a video resume for her.

When A blizzard shuts down the city, Marshall and Lily try to continue their longstanding airport reunion tradition while Ted and Barney volunteer to keep MacLaren's open so they can meet up with some college girls.

When Ted and Robin become "friends with benefits" to deal with conflicts they're having around the apartment, Barney tries to resolve the issues so they'll stop hooking up. Meanwhile, "reality" stars get too real for Marshall when they taunt him from the pages of his magazine.

Ted turns into an overprotective, older brother by going out of his way to keep his sister out of trouble when she comes to visit him in New York. Meanwhile, Marshall and Robin bond when he introduces her to a Minnesota themed bar.

Ted tries to prove he's not pathetic for getting left at the altar, and Barney tries to impress Robin, who thinks fighting is sexy, by fighting with patrons who are sitting in their favorite booth.

After Ted walks into the apartment to find Robin's date sitting on the couch in the buff, the gang realizes this method might be the easiest way to get their dates into bed with them.

Robin rediscovers the "Woo Girls," a group of single girls who like to go out and party. Meanwhile, Ted pitches Barney a design for his company's new headquarters.

When Lily and Marshall contemplate making the life-changing decision to have a baby, Lily turns to Ted and Robin for advice and their very different points of view on the issue.

While out for dinner with the gang, Ted runs into someone from his past that prompts each of them to think about how they would handle bumping into someone they'd rather forget.

After Stella and Ted make the spontaneous decision to get married in three days, the presence of their exes destroys what was to be the "happiest day of their lives".

When Ted discovers that the gang ditched their plans to stage an intervention for his engagement to Stella, he is adamant that they go through with it anyway.

After inviting the gang to Stella's apartment in New Jersey, Ted tries to sell them on the perks of living in the suburbs until he learns that she expects him to move there after they're married.

Television personality Regis Philbin meets a burger-mad Marshall while on his quest to find the restaurant where he had his very first New York burger.

As Stella responds to Ted's proposal, Barney realizes that he's in love with Robin.