Sent charlie first to get captured and later will go in himself to save Charlie and flip the switch.
I agree. I think he knew all along that Charlie needed to go in first to distract the people in the hatch, that would be Charlie sacrificing himself to get the job done. Preview for next week shows them beating Charlie up, maybe he falls in the water at some point and that is what Des saw and took it as Charlie drowning.
I think all along it has been Des's Destiny to keep Charlie alive to get to this point. Maybe this is a part of how Des is suppose to change, he was a very hard person when they first meet him and now he is more compassionate. The whole thing with Charlie and the flashes has made him, at least seem, more compassionate.
If you know the words to the Wonderwall song part of it says "cause your the one that saves me" (or something like that) maybe we were suppose to pay more attention to that.
Just some thoughts!