It's the year 2030 and an older Ted Mosby is telling the story to his son and daughter about how he met and will eventually marry their mother. This is where we meet for the first time Ted, Lily, Marshall, Barney and Robin.
In a desperate attempt for a second date, Ted invites Robin to a party he is throwing. However, she doesn't show up and he keeps throwing parties in the hopes she will finally arrive.
Ted agrees to let Barney spice up his love life and ends up on a crazy adventure of flying to Philadelphia, encountering the law and visiting the Liberty Bell.
Ted's outlook on his continuing search for love is altered when he rediscovers a shirt that has not seen daylight in years. Meanwhile, Barney amuses himself by coaxing Robin into sacrificing her job by saying completely outlandish things on air live for a cash reward.
Ted and Barney start checking out the club scene with their friend Robin whereas Lily and Marshall try to participate in some more "grown-up" activities as they draw slowly nearer to their wedding.
Ted makes his yearly pilgrimage to the rooftop Halloween party in search of a girl dressed as a pumpkin who he met years ago. Meanwhile, Robin is dumped after driving her new boyfriend away with her independent ways.
When a matchmaker with a 100% success rate turns Ted away because he is not compatible with any of the available women in her database, he is still determined that he is going to find his match. After getting information from the matchmaker’s computer, Ted pays a visit to a very cute but taken dermatologist in an effort to prove the prediction wrong that there are no women out there for him. Meanwhile, Marshall and Lily are obsessed with ridding their apartment of a critter.
As Lily becomes more of a permanent fixture in the apartment, Ted feels like he is being edged out of the mix by his engaged roomies. Petrified of being left alone and homeless, Ted tells Marshall that when he and Lily are married, he wants the apartment. The problem is that Marshall wants to keep the place, too, so they settle it like real "grown-ups" -- launching into a sword fight that leaves one man down for the count.
Ted and Robin are surprised to run into Barney when they volunteer at a homeless shelter on Thanksgiving. Lily is on the brink of freaking out when she goes to Thanksgiving dinner at her future in-laws house.
After being forced into knocking back 5 shots, so he will stop thinking, Ted goes on a partying rampage. The next morning he wakes up with a woman in his bed, but he does not know who it is. So he turns to his friends to try and piece the night together and work out who the woman is in his bed.
Ted rents a limo to take the gang out to sample five New Year's Eve parties in a quest to find the perfect celebration.
Robin accepts Ted's invite to a friend's wedding, but thanks to Ted, the couple may never make it down the aisle.
Ted finds a new woman at the wedding. They want to remember the evening so they don't exchange last names or numbers; but Ted takes a big fall when he tries to find out her name.
A mysterious tape arrives for Barney from one of his numerous ex-girlfriends, and the entire gang watches it. But, in order for them all to find out how she broke Barney's heart and made him into a suit-wearing bachelor, everyone must share their most embarrassing moment.
After agreeing to take things slowly and not have sex for a month, Ted and Victoria decide that they have waited long enough.
Things are going great with Ted and Victoria's relationship, but when Victoria is offered her dream job, the couple have to make serious relationship decisions. Meanwhile Marshall and Lily set out to purchase their wedding outfits and find out that none can afford what they bought.
Marshall interns at the corporation where Barney works and Lily finds that he is becoming a shallow jerk as he tries to fit in with his crude fratty coworkers. Meanwhile, Ted feels guilty when he receives several gifts from Victoria (Erika Singh) while he hasn't sent her anything.
Robin, who is very lonely, asks Ted to come over to her apartment after 2 A.M., but he isn't sure if he wants to go as he has a phone call on the way over with his friends, and with Victoria on his mind
Robin is nominated to receive an award for a news report and everyone needs a date to take to the show. Barney introduces Ted to Mary as a date that Ted can take to the show. Originally Ted is opposed to the idea of just trying to save face in front of Robin but when she shows up with a date he changes his mind. Robin asks Mary lots of questions, and Ted begins to really like Mary, despite her occupation.
Lily, Barney and Robin attend a high school prom to scout out a potential band for Lily and Marshall's wedding reception. In order to get in Lily and Robin pretend to be the dates of two kids who were going alone. Ted and Marshall are back at the apartment where they are preparing the invitations to be sent out.
When a matchmaking company calls Ted claiming they have found his soul mate, he is forced to postpone his date when Lily asks for his help.
Ted tries to keep Robin from going on a camping trip so that she can spend time with him. Barney enlists the help of an old flame to perform a rain dance. At the same time Marshall finds out about Lily's interview for the fellowship in San Francisco.