The episode begins and Lily is in labor and Marshall is in Atlantic City, but it's impossible to get a cab because of a big thing that Old Ted can't remember. Meanwhile, Ted and Robin arrive and Ted's freaking out, despite shouting that he's "not freaking out!" Robin is confident she can handle the situation because she once helped deliver a horse on the farm in Canada. Ted's more focused on putting out a kick-ass labor announcement email. Lily needs a distraction, so Robin tells her about her worst cab ride ever. Lily has another contraction. Meanwhile, Barney tells Marshall he'll get him to the hospital on time, but in return Barney wants to choose the baby's middle name: "Wait for It." That's the name.
So, for example, Barney Wait for It Eriksen. Now Barney and Marshall need to win a motorcycle to get to New York, so they have to play slot machines. To distract Lily, Ted tells her about Robin's "second base with Neil Young" story. It wasn't Neil Young. Robin then busts out the "Cuban Sandwich Crisis" story, in which she covered for Ted who had an explosive restroom situation at a party and took the fall for it when Barney accused her of causing the awful smell. Lily needs more stories, so she asks for "Where does that door go?" Ted recalls seeing a mysterious door at the bar and walking through it. Then Robin followed. Meanwhile, Lily gets a call from her dad, and is upset that Ted emailed her dad; who is the worst person to have around in a medical situation.
She recalls her dad sitting next to her telling her the awful things that could happen during her tonsil surgery. In Atlantic City, Barney tries to steal the motorcycle; unsuccessfully. Marshall, completely wasted, mutters to himself that he's on his way to Lily. But he can't get up two steps that lead toward the casino exit. Meanwhile, Ted tells Lily "The Tale of the Cursed Pants." Marshall is shown wearing purple and green plaid pants and says everything has been going wrong since he got them. He found a note written in Chinese in the pocket, which led him deep into Chinatown; where a dry cleaner gave him the suit jacket that went with the pants. Meanwhile, wasted Marshall is trying to get cash from an ATM, which he insists turned into a video game and some Web videos of chimpanzees in a karate fight.
Then it spit out his shredded card. Barney shows up and explains that he simply asked the guards. Barney found a bus driver who has two open seats headed back to New York. Back to the door story Barney follows and walks through. Meanwhile, Lily's contractions are now four minutes apart, and Marshall learns from the bus driver that the bus is headed to Buffalo. At the hospital, Lily learns she can't have an epidural. Lily needs another story, so Ted tells her about the time Barney tried to pick up girls as the Terminator. Robin tells her about Ted's "freakishly long arm hair."
Back to the door story, Lily starts to think she should check out the door, and she goes through. Ted then tells her about the time they tested if banana peels are really slippery, and the time they decided to go as The Breakfast Club on Halloween but failed to coordinate their costumes (they all dressed as Bender). Ted finally tells Lily about the time Lily went into labor, which is happening now. Robin looks under the sheet and tells Lily she's "rock solid" and can see the baby's head. Then she passes out. Just then, Lily's dad shows up. We see the rest of the story from her tonsil surgery, in which Lily told the nurse she had no idea who her dad was, and he was escorted away by security. Meanwhile, Barney and Marshall try to talk the bus driver into stopping in New York City.
The driver says unless there's an emergency he's not allowed to stop the bus. Barney sits down and tells Marshall he did all he could. But then something amazing happened: A bunch of the seniors on the bus stood up and declared they were having heart attacks. Marshall gets to the hospital. Meanwhile, Ted and Robin chat in the waiting room and decide to be friends. "I love you, Robin," Ted says, but he was just kidding. Marshall comes out and announcing he's a dad. Their boy is here: Marvin Wait for It Eriksen. Finally, Marshall is the last holdout and he slowly approaches. He opens it, only to have Ted, Barney, Robin and Lily all shout, "BOO!" And this brings us to Barney's wedding, where Lily tells Ted the bride wants to see him.
"How the hell did we get there?" Old Ted asks. Back to Marshall and Lily's baby, Ted tells Robin that's what he wants. Robin tells Ted he's "full of crap" because he's always chasing the wrong women. She says if he really wanted a family he'd stop pursuing women he knows he has no future with. He mentions Victoria, and Robin tells him he gave up Victoria so he could chase a "hot piece of ass." That was Robin. She tells him he should call Victoria. The last time he saw Victoria she was engaged, but Robin says that could have ended.