"Duel Citizenship" opens with a series of jokes about how Robin is Canadian and that makes her a little different than the rest of the gang. For one, she hangs out in a bar called the “Hoser Bar” and fights passionately with follow bar patrons while wearing a Vancouver Canucks jersey.
At the apartment, Ted and Marshall are reminiscing about their road trips to Chicago during the college days for pizza at Gazola’s. They decide to go on their first trip in many years the next day.
Robin finds out that she is facing assault charges from a guy she got into an altercation with at the Hoser Bar. Her lawyer advises her that she can avoid deportation if she becomes an American citizen.
As Ted and Marshall are about to go on their road trip, Marshall announces that Lily is coming. Ted is somewhat disappointed, as he hoped that it would be just like the old days.
Robin Practices for the American Citizenship Test
Barney helps Robin prepare for her citizenship test by quizzing her on American knowledge. Not to leave Canadians as the only victims of How I Met Your Mother humour, Barney spouts off a few comments about Americans such as, “Let’s go buy something that’s bad for us and then sue the company that made it. That’s American, Robin.”
After a frustrating ride that included many pee breaks for Lily and an audiotape about a dog named Sparkles, the trio arrives at the Crumpet Manor, where they will be staying on the way to Chicago. Turns out, the Crumpet Manor is targeted specifically for couples. Wowed by the possibilities of joint spa treatments, Marshall and Lily continue to be even more of an annoying couple, much to the chagrin of Ted.
After several rounds of quizzing, Barney declares that Robin is American, because she is belligerently sticking to her opinion on the quiz answers and insulting Barney, which is very American. Proud of her accomplishments, Robin goes out for a walk and is seen to be acting very “American,” that is until she is pulled back into the Hoser Bar.
Ted and Marshall go to Chicago, without Lily
That night at Crumpet Manor, Ted kidnaps Marshall under the pretenses of a beer run and drives them to Chicago, without Lily. At first, Marshall freaks out, but he quickly begins to enjoy his alone time with Ted.
After a crazy night at the Hoser Bar, in which Robin befriends a women’s curling team, she ends up in Toronto. Barney “flies across the ocean” to her rescue, urging her to come back to New York and write the citizenship test, instead they end up going for coffee.
At Tim Horton’s, the woman working there calls Robin an American, because she paid with American money and did not know the results of the Toronto Maple Leafs’ game the night before. Robin is incredibly upset that she does not have a country, because she is American to Canadians and Canadian to Americans. Barney stands up in Tim Horton’s and tells the crowd that if they are not going to accept Robin, he will gladly take her, and tells the patrons that they can “go back to being pointless.” He gets beat up by a group of patriotic Canadian men.
Although they make it to Gazola’s, it does not go as they had hoped. For one, the place is disgusting and overrun by bugs. Ted and Marshall get into a fight, in which Ted tells Marshall that he and Lily have become the same person. They end up apologizing to each other on the trip back to Crumpet Manor
Robin Decides on Dual Citizenship
Barney ends up having some nice things to say about Canada. He notes all the medical treatments he received after being beaten up, without being charged for them, and says that the coffee was really good. Barney says that if Canada plays its cards right, it could even become a state. Robin announces that she has decided to seek dual citizenship.
Back at Crumpet Manor, Lily is not even upset that they ditched her, because she is so relaxed from her spa treatments. Marshall and Ted end up feeling sorry for their trip to Gazola’s, as the pizza has made them sick.