The episode told of a three day snow storm and it was seperate into three stories that all came together.

Ted and Barney
The episode for the boys begins with them meeting two college girls they're hoping to sleep with.  The girls are in a band and the boys try to avoid seeing their band play and agree to meet them at McLaren's.  However, a snow storm ensues and Ted and Barney are left alone in the bar where they convince Carl to let them run the bar after he closes up.  We then learn two important things about Ted and Barney: one, they always wanted to start a bar named "Puzzles," and two, that Barney is just one school away from party school bingo (a game he invented).

Surprisngly the girls eventually do arrive and they bring their band with them... their marching band.  The boys invite them all in and run McLaren's as their own bar, Puzzles.  However, when Carl calls to tell them he's coming back, the boys call last call.  When they overhear two other guys talking about starting their own bar and never having last call, they're reminded of themselves and have everyone back to their place for no last call.

Marshall and Robin
Marshall and Lily have a tradition where when one of them is coming in on an airplane, the other picks them up with a chaffeur sign and the other arrives with a six pack of a funny-named local beer.  However, after reading Cosmo Girl, Marshall decides their relationship is maturing and he doesn't need to pick her up this time.

When Robin convinces Marshall that Lily will definitely have a six pack waiting for her, Marshall makes Robin drive him to pick her up.  The two, however, get stuck in the snowstorm and under a big bed of snow pushed on them by a plow.  When Marshall calls Robin an emotionaless robot, she gets them out of the car through the sunroof and they go to the airport.  However, when they arrive, there's no Lily and Marshall checks his phone to find a message she's stuck in Seattle due to the snowstorm.

Lily
Meanwhile, Lily's story, which is being told concurrently as Marshall's, leads you to believe she's arrived the same day as Marshall.  After a woman on her plane convinces her Marshall is going to be at the airport, she realizes she doesn't have the six pack to greet him with.  When she arrives an hour early, she makes Ranjit (we missed him!!) take her to a local beer importer so she can get a Seattle beer in New York.  However, when she comes back to the airport, there's no Marshall as he arrive there two days ago and saw that as a sign not to pick her up.  Then suddenly we see a band slowly showing up playing a sad song as Lily sits alone.  Then, out of nowhere, Marshall shows up with the sign.  He used the marching band.