<P> Chastened by Marshall's father's fatal heart attack, the gang all go to get their hearts checked, except Barney, who is too scared to go alone . Lily agrees to accompany him so long as Barney promises her to never lie to his new girlfriend, Nora . When Barney visits the cardiologist, she requests that he wears a heart monitor for 24 hours, citing a possible arrhythmia . The next day, Barney and Lily return to the doctor, who notices some oddities in the readout . She asks Barney what happened at these certain times, and Barney tells the story of the last 24 hours . </P> <P> At dinner, Barney became worried when Nora began talking about marriage and settling down; he claims he wants the same things . After dinner, Barney blackmails the group into pretending this is true . Nora tells everyone that her parents are in town and invites Barney to meet them the next day . However, Barney admits that he was lying about wanting to get married and Nora slaps him . Lily and the cardiologist also slap him when he tells the story . </P> <P> Meanwhile, Robin says she is going to get a dog, but Ted forbids it because he thinks that he will end up caring for it . Instead, based on Marshall's advice, Robin finds a boyfriend . He is nicknamed Scooby, and his behavior closely mimics a dog, which causes the gang to make a series of puns and jokes, to Robin's annoyance . When Robin goes to work, Scooby and the rest of the gang consume marijuana (with Ted replacing it with sandwiches in his story to his kids). While the others are high, Scooby goes missing . They eventually find him urinating on a fire hydrant, only for him to get hit by a car when he runs across the street . </P> <P> Lily insists that Barney genuinely does want to settle down and get married, but Barney denies this . Nevertheless, Barney goes to the brunch to tell Nora about his feelings; he enters the restaurant, seeing Nora with her parents, and makes a heartfelt speech . Nora forgives him, and introduces him to her parents . However, the scene turns out to be a figment of Barney's imagination, and he leaves before Nora sees him . </P>

Season 6 episode 18 how i met your mother