Yay! People in here are discussing this episode and how it's going to affect Grissom! May I join in?
As Hankster pointed out, early on we really saw Grissom have a reaction to cases involving children. I remember watching "Blood Drops" for the first time with my fiance, and being shocked that Grissom grimaced over the body of the little boy. My fiance told me, at that moment, that cases involving kids are one of the few things that really get to Grissom.
It also makes sense why "Gum Drops" was originally planned for him. It was all about a missing girl. Here, Grissom gets two missing boys. And, I love it, because he's already stressed out. The man grimaced when he saw the beaten face of the dishwasher in "Fannysmackin'." It was an obvious reaction from him because it's something we're used to only seeing with children. This shows me that Grissom is already being pushed, his emotions are already close to the surface, and this episode could only push him further.
The previews show that Alan Tudyk's character is screwing with him. The two are playing a game, one that Grissom really doesn't want to play. His migraines return. The last time we saw these? The last time he was nearly pushed to the edge, with Paul Milander.
I think this episode is going to be a great character study of Grissom as we get to see what the pedophile guesses right, and what he guesses wrong, to see who wins the game. I definitely think that this episode will push him to the edge. All the previews have seemed methodical, slow, but not slow-moving. I have this feeling of a game of chess, of two opponents taking in the board and taking in each other for a very long amount of time before making a move. I can't wait to see who wins, and how that will affect Grissom further.