Robin's an ace reporter, so she suspects this isn't just about the burger. Lily explains that Marshall really needs to get a job, and Ted encourages her to tell them about the underpants. Flashback to Marshall: he's lounging on the couch in a T-shirt and a pair of boxers, yelling at what must be the Million Dollar Heads or Tails game show. ("It's almost usually heads!") Lily returns and thinks it's funny he never put on pants that day, but back at the restaurant she explains that soon, it became a daily thing. She was grateful that he wasn't leaving the house like that, but then one day he opened the door to get the paper, while just in his boxers. The next thing she knew, he was going down to the lobby to get the mail, in the same state of undress. Ted says, "Everyone's got an underpants radius. For most of us, it's the distance from the bedroom to the bathroom, but as your self-esteem gets smaller, your underpants radius gets bigger." Madonna must be a wreck.

Robin asks how big Marshall's underpants radius is, and we flashback to one of the many scenes we saw earlier, with Marshall and Lily trying out different burger joints. This time, when he says "We're going," and goes to leave the Vegetarian Burger place, we see him stand up, wearing the same cruddy old boxers. The writers say, "Underpants in public site gag? Check."

Knock-knock!
Who's there?
Tom Sawyer.
Tom Sawyer who?
Tom Sawyer underpants in gym class.

Barney tries to cheer the group up by singing the inspirational Goliath National Bank jingle, but it's his hushed, "Member FDIC," at the end that makes it. Lily says they have to find Marshall that burger. Ted says they're all eating the burger, but Robin says, "I'm not," because hers still hasn't shown up. Oh, Robin, you've slept with two of these people. Toughen up, get a knife, cut off the side of Marshall's burger that he bit, and eat it. The waitress finally brings Robin's burger over, but she's delayed in setting it before Robin when Lily asks if they changed cooks or something. As the waitress explains that this restaurant is modeled off of another place on 106th and Manhattan Avenue, Robin reaches for her meal. She gets it just as the others rise to exit, so she leaves it. Unbitten! Robin, eat the frigging burger and catch up with them later. You know where they're going. They leave the restaurant. Without paying! Gimme that baseball bat Marshall and Ted were wielding eight years ago.