Robin: Barney's lost it. He needs an intervention.
All: Oh!
Lily: Robin, after everything we've seen, do you still think Barney's faking this?
Robin: No, but we have to stop it. Barney is not Barney anymore.
Ted: Well, people change.
Robin: But not this fast and this drastically. This is a cry for help, okay? If I was out of control, I would want you guys to help me. So, what do you say? Intervention?
Marshall: Intervention.
[later, when Robin arrives at the apartment, Ted, Marshall and Lily are standing beneath the "Intervention" sign:]
Robin: Oh, good. You're all here. Um, when Barney shows up, it's important for him not to feel ganged up on, so, let's start with, um, "We love you, and we're worried about you."
All: We love you, and we're worried about you.
Robin: Oh. Great. But you know, with less pity in your eyes.
Lily: Sweetie, sit down.
Robin: Uh, no. Only the person getting the intervention sits down.
All: Yeah.
Robin: Oh. Please tell me this is about my drinking. Damn it.