Little Minnesota

Little Minnesota is the second Christmas special of How I Met Your Mother.

Plot
Robin enters MacLaren's wearing an unseasonal t-shirt and explains to Ted that the cold weather doesn't affect her because she's from Canada. Marshall agrees and compares New York in winter to a spring day in Minnesota, except for all the taxis, skyscrapers and non-white people. Upon returning from the bar Ted explains that his sister Heather has arrived in New York and is planning to move there. He explains to the group that Heather is something of a screw up (having taken six years to graduate from three colleges, during which she crashed two cars, got married for five days, and sat in a tree nobody was planning on cutting down for nine weeks) and expresses his doubt of her ever actually moving to New York, telling them of the time she sold his possessions to buy tickets and travel to a Nine Inch Nails concert in Spain. When Barney calls he ignores it and Lily explains that he has been keeping Heather and Barney apart for the years she has been visiting New York.

Heather arrives and the group discovers Barney waiting for them at Ted's apartment with a rented swivel chair he brought for the occasion and a glass of brandy. Because of her inability to keep secrets, Lily admits tipping off Barney of Heather's arrival and reveals Robin's Christmas gift for Ted.

Barney is hurt that Ted tried to keep him away from Heather and explains that he never intended to act on all the inappropriate jokes he made. Ted explains that he does not trust Heather or Barney, though he relents and invites Barney to dinner with them on Sunday.

Robin is homesick and so Marshall takes her to the Walleye Saloon, a Minnesota-themed bar that he goes to when he is feeling homesick. Unfortunately she likes it so much that she ends up pretending to be from Minnesota to win the friendship of the bar patrons, much to Marshall's frustration. His frustration grows when she claims his story about the 1999 NFC championship game as her own and boils over after she beats his high score on the Fisherman's Quest video game, at which point he unmasks Robin as a Canadian.

Over dinner, Heather and Ted discuss her decision to move to New York to work in finance and she asks him to co-sign the lease of an apartment she found. However, his lack of faith in her proves an obstacle. Frustrated with Ted's insensitivity, Heather and Barney stage a fake sexual encounter after their interview at Goliath National Bank and ensure that Lily walks in on them, knowing that she won't be able to keep it a secret from Ted.

Heather and Barney persist in taunting Ted until he confronts them at MacLaren's, claiming that Heather has never changed her attitude. Barney explains the plan to the surprised Ted and Lily, at the same time revealing that he kissed Ted's mother. Heather storms out to find a hotel, expressing her anger at Ted's refusal to accept that she has grown up.

Eventually Ted makes up with Heather and co-signs her lease, telling her he wants to get to know the new her. Marshall apologizes to Robin for outing her as a Canadian, and reassures her that despite her lack of job or boyfriend she still belongs in New York with her friends. To help ease her Christmas homesickness he takes her to a Canadian-themed bar, the Hoser Hut where he sings Let's go to the Mall much to Robin's shame.