Dan's like, "Okay, I have to go to this internship meeting at 2:30, so let's meet up before that," and Serena's like, "Sure! Now, is that AM? Or PM? Parisian Left Bank, or somewhere in Maryland? On Earth, or Mars in the 17th Century? You know what, let's just say all of the above. Ciao!"
Chuck whisks S away to a den of scheme, and explains that during Family Brunch -- since he's, you know, never invited -- he went to the Palace and cracked the Bart safe and got a key to Lily's safety deposit box at the nonexistent Dorset Bank on Madison. So the plan is: Dress up Serena like Lily and get in there, because that's at least three levels deeper than they've ever gotten as far as the neverending paranoid security measures of their family.
But also, again, on the surveillance level that is the prime thing of this show, you have Serena dressing up like Lily -- after having just been dressed-up-as to an unprecedented and chaotic degree -- while also stepping into what she thinks are her mother's shoes. Lily's becoming Bass -- treating Serena like Bart used to, treating Chuck like Jack always does -- so Serena has to step up and play the classic Rhodes role. Once again, Serena's trying to take control of the image, the simulation, and she's going to fail, because that's just assuming the same role as all the people constantly doing that to her: Not actually solving the equation.
And then you've got Chuck dressing his sister up as his mother, hands jammed down his pants, which is just too obvious (given the ongoing fashion/burlesque themes of both his sexuality and his power games) to warrant much beyond a nod to Hitchcock, a side note that this is as close as he'll get to having either of them and it's nearly enough, and much gleeful applause for the many fucked-up things he'll have to say about it.
El Capitan has never been healthier, and his son's a total pothead getting on in years, so it makes sense that he is Vanderbilt-hale on mile nine of their jog, while Nate is gasping like a gunshot victim. (Needless to say, neither of them are even slightly sweaty, but Nate does a good job of pretending to be winded for the purposes of this scene.) Nate's still nattering on about getting a job as ordered by the parole officer, and Captain's still not that interested, but then Nate mentions how he's Chuck's date to Thorpapalooza, and maybe meeting up after to celebrate the job the Captain's apparently gonna get today. The Captain's tail starts wagging the second Nate mentions Russell Thorpe, but red flags are not Nate's specialty, and anyway the Captain just ran off in the middle of this sentence to find a lady jogger to bone.