Plot

The gang encounters a guy at the wedding who intentionally stirs up trouble among them, and Marshall finally arrives at the Farhampton Inn.

Marshall and Marvin are almost at the Farhampton Inn, they who get a ride for the final stretch from an unexpected source, the driver who seems to know just a little too much about Marshall's life without he knowing who she is. Meanwhile, someone associated with the wedding that neither Robin or Lily seems to know approaches them. As they try to figure out who he is, he ends up working his charm on them, before something he says ends up driving them apart, perhaps forever. That same person does exactly the same thing later with Barney and Ted. Marshall's current chauffeur may be able to shed some light on who this person is, and why a "bass player wanted" ad is the final straw for her in wanting to get her revenge on him. And Ted and Barney discuss what Ted sees as Barney's overuse of the phrase "that's the dream". They have to decide what really is "the dream" for both of them.—Huggo

At 10 p.m on Saturday, 20 hours before the wedding, Marshall starts walking to the Farhampton Inn with his baby son Marvin in tow. He starts out full of ambition but quickly runs out of steam. Just as he is about to give up, a woman driving a van stops by and offers them a lift; it is Ted's future wife; and, as Future Ted notes, that's how Marshall met her. Marshall and The Mother talk along the way and The Mother starts telling him excessive details about his life-only to admit she already knows everything from meeting Lily earlier in the day.

Meanwhile, at the Farhampton Inn, Lily, Ted, Robin and Barney sit around longing for their bottle of scotch-and for Marshall. A man suddenly swings by Lily and Robin and confidently tries to get to know them better and flits to Ted and Barney from time to time. However, it is the beginning of a dispute between the two women, as their conversations with the stranger lead to him claiming that Lily wants to ruin Robin's weekend by lamenting all the time about Marshall's new job and the plan to go to Italy. He also reveals that Robin is secretly rooting for Marshall. Robin explains that she wanted Marshall to take up the judgeship and avoid losing Lily as her best friend. To make up for their dispute, she encourages Lily to use Marshpillow as a punching bag.

The man's conversations with Ted and Barney also results in them arguing as well. When the man suggests Ted try Gazzola's Pizza while in Chicago, Barney is shocked to discover that Ted's moving to Chicago to take up a new job; he is even outraged at learning Ted is leaving the day after the wedding. Embittered at what he feels Ted is trying to diminish their friendship, he storms out. Ted makes it up to him by presenting him a 30-year-old bottle of Glen McKenna he stole from the liquor store (through earlier advice from Lily). Barney appreciates Ted's efforts to get him a bottle (even if he is arrested for theft), but comes to the realization that Ted wants to start anew in Chicago to get away from Robin. They hug and admit they will miss each other.

The Mother tells Marshall that she's going back to the city after she drops him and Marvin off at the inn. When Marshall asks why, he learns that The Mother is part of the wedding band that will play at the reception, but she wants nothing to do anymore with the lead singer named Darren (Andrew Rannells). She reveals that Darren-the man who has just pit Lily against Robin and Ted against Barney-is known to manipulate people for his own ends, citing how he joined her band and later maneuvered to replace her with another bass player. They agree about being too nice with other people and resolve to take a stand when they arrive at the inn. Marshall and Marvin reunite with Lily, who immediately pauses the upcoming confrontation as she is simply happy to see her husband and son again. The Mother practices her speech, but Linus the bartender cautions her and implies about letting karma take its course.

As The Mother sulks about not having had the chance to finally stand up to Darren, she sees him sporting a fresh black eye. Darren tells her the best man-Ted-punched him hard in the face for "no reason", when in reality he knocked the Glen McKenna bottle out of Ted's hand (Ted was sharing it with his friends to celebrate Marshall's arrival). The Mother's amusement at the situation causes Darren to quit the band on the spot. Satisfied at the outcome, The Mother orders a double of their best Scotch in stock for the best man. Later on, after The Mother had already left, Linus gives Ted his free drink and is amazed that it is a 35-year-old Glen McKenna (Future Ted says it was the first time his future wife bought him a drink). Ted and Barney are surprised that the bar actually served a slightly older Scotch (Linus points out they had never asked if they did).

Marshall apologizes to Barney for missing the rehearsal dinner, and offers a gift after the wedding as consolation. Barney mocks him for missing the dinner and dares him to give this apology gift now. Marshall agrees and gives it to Barney: the beginning wind-up of a slap. Barney realizes it's another slap coming, and the screen cuts to black with the words "to be continued..."