Which is where the whole episode starts unwinding around itself, because all you needed to hear was that line to know how all of this would play out: Once again, Lily is the Bad Fairy doing Good Things and refusing to explain it, because once a spy always a spy, and she cannot but vainly hope to live a normal life outside the Guild of Assassins where she was raised.
"Yes, Penelope. You will stand in the cold and hail me a cab. Call me when it's curbside. And show some leg if you have to, I'm already late for Indra." Blair laughs in Serena's face when she shows up looking for Dan almost a half-hour late, and S almost feels bad about fucking him over again, and suddenly it's Reality Check Time. Number one, why are you so obsessed with stupid Ben that you would hurt your best friend besides me; number two, you have no idea who Ben is now after all his time in the big house -- "They're all good men before something happens to them, S" -- and number three, essentially, you are the bad thing that happens to them usually, which number four, why are you being such a bitch to Dan.
Serena's head joggles from side to side with that one, which is stated only very obliquely, but it's nice because she responds to the implications and not the words: "I thought you hated Dan." Blair nods awesomely: "I do. So very much. But whatever it is that you see in him, he seems to see in you as well. I know you want to focus on Ben, but maybe you're avoiding your future, not fixing your past."
And so very many loving props to Blair, the immune system/security dog/bodyguard of the entire Upper East Side, for this characteristically sudden and sharp acceptance of Dan as one of the many innocents she has to shepherd and protect. You know she didn't think about it even a second -- doing so would shrivel her like the Witch of the East's Jenny-striped stockings -- but just leapt intuitively all the way to:
"Love you, Serena, but this isn't okay. I've already mentioned it once and you continue to disobey me, so I've stepped up to oblique references. Next alert level is Yellow, and just trust me when I say you don't want to get there. Now get with the program and accept the fact that Dan is your Future, because I really need him off the fucking market."
I don't think I've ever felt closer to Blair Waldorf, in four years. That is a little too close, if I'm being honest, for comfort. Anyway, Chuck calls to tell S about his meeting with Lily and the guitars and explicitly says, "Lily is trying to do the right thing by the company, and by your inmate, too. She said she'll prove it in 24 hours." All true. And of course S is like, "Fuck that. Fuck her 'words' and fuck her 'intentions' and fuck your 'high road' and 'confirming this story.' Like this was ever about anything other than taking her ass down, like Ben matters, or ever mattered. Idiot. But yeah, I'll give you a 'day.' I don't even know what that word means anyway, so you just let me know when it's tomorrow, and we will bring it on."