Just keep remembering, as far as we know, it's only a 'major-ish' character leaving. And that character leaves in episode 23.
As for the finale- that's an entirely different deal. That's the one with the serial killer and such... we don't know who (IF ANYONE) dies then. I have heard nothing about someone else leaving the show, so I'd be shocked if they were to kill someone off. Just keep thinking of NY. For those of you who don't follow it, last season they said someone was going to die- which det Angel was shot- and pronounced dead. Shortly after, they were all out at a bar, and THAT'S when the shootout happened. Someone did a drive by to the bar they were all at, and the show ended with the cliffy of the windows all shot up and EVERYONE one the ground, so you had no idea what was what--- until September where we learned everyone survived, but one (Danny) had an injury that is already healed up by now.
So the HUGE deal of the season seems to end with episode 23. With the car bomb, and the diamonds being found. Just think about who you see in the finale, and that may help all of you put your minds at ease.
Just my 2 cents!