The Breaking Points
Marshall and Lily's bedroom: Lily sits up in bed, coughing her lungs out. When Marshall sleepily inquires if she's okay, she answers, "Actually baby, my throat's a bit sore," in Harvey Fierstein's voice. She talks like this for the rest of the episode, so let's call her Lilystein.
Ted's Building: He runs up the staircase. By the time he's on the third flight, he is sweating profusely and gasping for air.
MacLaren's: Barney gives an unseen someone a how-you-doing nod, and as he grabs his phone out of his jacket pocket, he sees the huge burn on his tie. He screams like a baby.
GNB Roof: Marshall and Arthur are sharing a smoke, and Arthur is telling an awful story about hitting someone across the nose with a newspaper. We're supposed to think it's the dog, but it's obvious from the previous scenes that it's going to turn out to be anyone but. In this case, it's his son. As Marshall is still digesting that warm, fuzzy moment, Arthur has a heart attack. He grabs his left arm in pain, and as he's dropping to the roof he says, "Michael, call 9-1-1!" Marshall whips out his phone and pauses. "It's Marshall, by the way." Arthur screams as Marshall dials. Commercial.
Ted's Roof: Marshall, Lilystein, Ted and Barney are sharing a smoke. Marshall must have just caught them up on the news about Arthur, because Barney's hoping Arthur is okay and/or calling dibs on his office. Ted declares they have to quit smoking. Lilystein agrees: "Honey, you said a mouthful." Marshall wishes he never started. He wishes he could confront his 13-year-old self, before he started. And in Marshall's fantasy, big Marshall approaches 13-year-old Marshall on the camping trip and punches him in the gut. Back in reality -- back on the roof, Marshall says, "I hate that little bastard." Hee. Lilystein croaks, "Me, too." Me, too. They decide to do it and three of them snuff out their butts. Meanwhile, Barney smokes away. "Well, I am proud of you guys. I have heard how difficult it is for smokers like yourselves to quit, so on behalf of nonsmokers, I salute you, and I am here to help. So, hand in your cigarettes, and I will get rid of them. One at a time." Lilystein grabs the cigarette out of his hand. "You're quitting, Dollface. I know I don't normally call you 'Dollface,' but it kind of works in this voice. Dollface."