When Ted and Barney argue about who has "dibs" on a hot girl, Ted realizes that she is there with Cindy, a girl he previously dated who is also the roommate of his future wife. Meanwhile, Robin is heartbroken over Don, and Marshall can't keep quiet about his desire to start a family.

When Barney convinces the gang to help his mom move out of her home, they quickly learn that she has been very protective of Barney and lied to him about events throughout his life. Meanwhile, Ted gets upset when Robin oversells him to a blind date.

Barney uses his best womanizing tactics to try to convince Ted to design the new GNB building; Robin drunk dials Don.

When the gang teases Robin about not being a real New Yorker, she sets out to prove them wrong by racing to catch a glimpse of Woody Allen.

Ted becomes conflicted after meeting an attractive woman who is passionate about saving the landmark building being torn down for his new project.

Marshall and Lily try to figure out how to conceive a baby with the gender of their choice; Robin's perky new co-anchor irritates her.

When Zoey enrolls in Ted's class, she manipulates his students into taking her side in the fight to save the building being torn down to make room for his project. Meanwhile, Marshall and Lily spot Robin marching in the Halloween parade of shame.

When the gang goes to a black tie event at the Natural History Museum, Ted gets introduced to Zoey's husband, The Captain.

Barney's discovery of a Canadian kids show called Space Teens, that Robin appeared on as Robin Sparkles, leads the gang to get her to reach out to her co-star, Jessica Glitter.

When Ted leaves the bar early to prepare a Thanksgiving feast for his friends, the gang winds up partying all night with The Blitz, an old friend from college who has bad luck. As a result Ted is forced to spend Thanksgiving with Zoey.

When Ted's new friendship with Zoey tests the theory that single men and married women can't be friends, he invites her husband, "The Captain," to hang out with them. Meanwhile, Marshall and Robin decide to spend alone time together, and Barney and Lily possibly have a fight.

Lily and Marshall receive shocking news that has a profound impact on the gang. Ted begins his duties as best man for an old friend's wedding.

Afraid they will never get pregnant, Lily and Marshall decide to see a specialist. Robin begins her new job.

While on a trip to Minnesota, Ted and Barney try anything to make Marshall laugh. Marshall runs into an old nemesis from high school.

Barney gets emotional when he opens up to Honey about his life. Ted admits to having feelings for Zoey to the group.

Barney declares February 13th a holiday for desperate women. Marshall receives a Valentine's Day surprise from Lily. Zoey and Ted work on figuring out their relationship.

Marshall becomes obsessed with saving the environment after seeing a documentary on garbage. Ted runs into The Captain. Barney admits he has feelings for a woman.

When Barney starts to have real feelings for Nora, he worries that something is wrong with his heart. Meanwhile, Robin starts dating a guy who acts a lot like a dog.

Barney meets his father and is shocked by the differences in their lives. The rest of the gang learn their "gaps"; knowledge they should have by now, but don't.

Lily and Barney react badly when Marshall finally quits his job at Goliath National Bank to take a volunteer position at an environmental organization. Meanwhile, Ted and Zoey's opposing positions on the future of the Arcadia come between them.

When Barney tries to bond with his father, he asks the gang to help make his life seem more exciting by lying about their own lives. Meanwhile, Robin runs into a guy she has a crush on.

When Marshall and Barney argue over the destruction of the Arcadian Hotel, Robin and Lily try to mix the right combination of cocktails that will force them to make up. Meanwhile, Ted plans a romantic weekend away with Zoey.

When Ted is faced with an important decision that might affect his future with Zoey, the gang expresses their true feelings about her.

Robin and Barney bond when they intervene in Ted's relationship, and Marshall and Lily watch a ticking clock as he fears that he soon will be the victim of food poisoning.

On their way to Long Island for their wedding weekend, Robin and Barney come across a startling family discovery. Meanwhile, Marshall sees something online that changes the course of his journey east, while Lily confronts Ted about letting go of Robin.

When James reveals that he is getting divorced, Robin worries about how Barney will take the news. Meanwhile, Marshall races to find a way to get to New York in time for the wedding, and Ted deals with being alone at a romantic hotel.

When Lily discovers Ted’s list of things he wants to do in New York before he moves for Chicago, she becomes frustrated that she is the only person who knows about his plans. Meanwhile, Robin and Barney realize they have very little time together before their relatives arrive for their wedding.

While Barney works through his anger at Ted after finding out he still has feelings for Robin, Marshall Skypes in to act as a judge and help settle their dispute. Meanwhile, Lily realizes she is Robin’s only girlfriend.

Barney is upset after Robin wins James's wedding ring during the poker game, and Ted argues with Marshall and Lily over whether he gave them a wedding gift.

When Ted finds himself with three prospects to be his date for the wedding weekend, he chooses poorly. Meanwhile, Barney and Robin have a confrontation with their minister, and Marshall learns more about his driving companion, Daphne.

When Daphne sends a troubling text message to Lily, Marshall enlists the gang's help to remove the message while enforcing the "No Questions Asked" rule.

When Robin and Loretta's conflict escalates, Barney is caught in the middle. Meanwhile, Marshall and Daphne deal with a stowaway on their road trip, and Ted and Cassie try to enjoy a trip to a lighthouse.

During a flashback, the gang wonders how the Ted, Robin and Barney love triangle will play out; Barney accepts challenges from Robin and Lily.

Barney concocts a plan when his father arrives at the hotel; Ted thinks he is being framed when a wedding-related duty gets messed up.

Marshall tries to get Marvin to sleep by reciting rhyming bedtime stories.

Robin is dismayed when Barney wants to have their rehearsal dinner at a laser tag arena; Ted aggravates Lily by not following through with a promise.

A man at the wedding intentionally stirs up trouble; Marshall finally arrives at the Farhampton Inn.

In an attempt to deliver a devastating final slap to Barney, Marshall explains how he mastered the Slap of A Million Exploding Suns.

Robin and Ted try to get Barney to reveal secrets after he drinks too much; Marshall tries to avoid fighting with Lily.

The mother reveals how she met Ted and what she has been doing over the past eight years.

Robin and Ted reminisce about past relationships as they search for a drunken Barney on the day of the wedding; Lily and Marshall come to a resolution; Barney befriends two men who are eager to meet women.

The gang must figure out how to make the Stinson Hangover Fixer Elixir to help Barney recover on the day of the wedding.

Robin and Lily have a fight on the morning of the wedding; Barney can't decide what suit to wear; the gang watches a movie that Ted didn't want them to see.

Marshall asks Barney and Ted for help figuring out where Lily went in the middle of the night during their argument.

When Gary Blauman shows up at the wedding, it sends the gang into a frenzy as they each recall an encounter with him.

With only a half an hour left before the wedding, Robin and Barney panic; Lily and Marshall rewrite their wedding vows.

Ted finally finishes telling his kids the story of how he met their mother.

Ted finally finishes telling his kids the story of how he met their mother.