Where can I even begin?? Since Keppler's first appearance and his sketchy methods, I didn't really know how to feel about the character. He is a great CSI, but there was something odd about him, and now we know what. To summarize (if you didn't watch the episode) Keppler killed an innocent man in Philly b/c he thought that the guy had raped and killed his girlfriend Amy. (The girl who has been previously mentioned in other episodes) Turns out that her own father killed her and has the gun that Keppler used to kill the innocent guy. The father is a suspect in Vegas for the murder of a fellow cop from Jersey who was in on the whole messed up thing and the hooker he was with, and it turns out that there was another girl in the room who the father didn't see, so she is out on the streets. When the Vegas gang start to realize who the real murderer is, the father leaves the Keppler gun in his hotel room. They find blood and Keppler's prints on the gun, think he's either being framed or is going to kill again. Catherine hopes for the best while the guys try to track down a now vanished Keppler. Keppler has detached the GPS from his SUV and ditched his phone (which proves important later) Keppler finds the witness girl in a hotel and calls the father. The father is thinking that he will kill the girl and be done with everything, but Keppler tries to save the girl as she runs out the hotel door, the father fires a round at her and ends up hitting Keppler. Catherine runs into the room and the father points the gun at her and Keppler with the last of his strength fires 3 shots at him killing him. Catherine rushes to Keppler's aid, and he dies in the ambulance. (Sad I Know!!!) Later Nick and Warrick are finding where Keppler's phone is and it turns out that Keppler had put everything needed to solve the murder of the cop and hooker into a cooler for them to find.
Oh, and GRISSOM RETURNS!!!!
I think that just about covers it.
So basically the only episode that I like Keppler in is the last episode that he appears in (alive). The episode had excellent writing that made you think and try to figure out what was going to happen next. There was only one scene with Sara and Grissom together, and it was less than romantic. Greg only appears once, and we find out that Nick is a butt man. So once again, the sketchy Mike Keppler died in the line of duty protecting Catherine. RIP Keppler, your creepiness will be missed.