It sinks in. Diane and Kalinda are like Oh girl and refuse to tell Celeste who it is by name, to the point that you suddenly realize we haven't even hit the credits yet, so obviously "CS" is going to be a huge reveal. So then you're like, "Whose initials are CS? Is there a political celebrity or, I don't know, a recurring guest star who plays a... HOLY SHIT!" and then everything starts moving real fast.
Diane: "Mother of God."
Kalinda: "Well, he's a crazed creepster that might not even help us."
Diane: "He will if we send Alicia. He loves her ass."
Which, I love that they did that right up front: Along with political contacts and a preternatural charisma on TV, Alicia also brings with her the admiration, not to say friendship, of a perverted serial-killy murderer.
Which positions it correctly, for the series and the episode, because the problem most shows face with a character of this magnitude is "not enough/too much," you know, like on crime shows there's always this one Irene Adler Hannibal Lecter mastermind that's obsessed with Our Hero, or a theatrical Grande Dame that plays somebody's crazy grandma, and if they do too little then it's this perennial event, and if they do it too much, then you're Betty White and everybody gets over it.
I think for a lot of people the acclaim of this show has to do with the "Characters Welcome" sort of approach -- you get to see the best actors doing the most insanely well-written and well-rounded characters -- and so it's like a play they're putting on for us. But for me, it's more often the story of Alicia, because I identify with her -- her secret desire to be Captain America, her rigid self-righteousness, her chronic inability to discern the difference between the two -- so much. I think it's the most dynamic thing about the show, that it manages to be both an ensemble and a biography, which makes the best shows (again, Buffy being a great example) what they are. Finding your place in the emotional and symbolic landscape made up of the people around you.
So because the show is, at least in large part, about what these people signify about Alicia, this aspect of the show sets its own limitations simply by existing, because every character works the same way. Louis Canning, Patti Nyholm, Nancy Crozier, all of them highlight and confront us with different parts of Alicia, and this guy is definitely on that order. (Rather than, say, the cornucopia of Wacky Judges or various Dark-Yet-Quirky investigators, both of which classes of character have different reasons for being how they are, or Rita Wilson and the bevy of other powerful women Diane's always up against.)