An analysis of this as the the "season ender", as well as some consideration of the show after Grissom/Petersen left, and what is needed for the show's future.
As far as this show, it's really not much of an ender -- no surprises, revelations, closure, not much of anything... it's just another CSI ep.
I suspect part of the problem is that they were supposedly going to end the show with this season, then everyone, including Fishburne, signed back on to keep going.
As the top-rated scripted show on TV, quitting with the ratings that high would be stupid for CBS or any of the business people, if there was an option... as a result of retaining the show, however, whatever they might have been planning as a big blow-off went out the window.
So they wound up grabbing a story out of the "not quite good enough" pile and cleaned it up a bit... possibly not this ep, but one of the last half-dozen or so eps. My guess would be
Gone Dead Train, which seemed like a retread in many ways of previous eps, with a slightly different macguffin.
To my mind, after
One to Go, this season is a weak hodgepodge of fairly entertaining stories. There were a couple decent eps, for sure, but it was more like an effort to make everyone happy with screen time so they'd sign on for more. Hopefully, they'll use the break to refine their concept of how the show is going to work with Petersen gone. Fishburne is a good actor, as good, I'd say, as Petersen, but the character is less naturally the centerpiece of the show, so they'll have to develop it somewhat to identify how the whole crew works together and redevelop the camaraderie that it lost when it lost three regulars. While the show has always been about the details, the people are more central to it than many grasp.
One thing that I haven't seen is any sort of tension in the show regarding the "lost friends"... it's one thing when you lose one person you'd known for years, but when you lose half of the team you've worked with, that's a big impact on the individuals involved, and so far, they're two short on actual crew. Riley's nominally taken one of those spots, but they really haven't defined her character at all. She's pretty much a cipher and a pretty face, nothing more. They've done nothing with her background to this point, that I recall.
Replacing Riley's character development has been a lot more time spent on the background crew -- Hodges, Wendy, David, and Al. Only Mandy and Archie got almost no extra screen time since
"One to Go". These people, while important, can't be quite the focus of CSI -- they aren't in the field and thus are only peripheral to pulling the case together, so, while character development is good for them, they can't take the place of the "missing member" of the CSI crew, especially without Riley as a full member. They provide information, but, in the show at least (if not the real world), the CSI field member, and their supervisor, are the ones who put together the pieces to explain the puzzle. Sure, there are exceptions, but, for the show at least, it's the field ops who do the solving.
So that suggests we should be looking for three things with next season:
1) Development of the camaraderie of the show with three major cast members replaced.
2) Character Development -- Fishburne (already well on the way) and particularly of Riley, if she remains. Also, Catherine's character needs to be shown to step in and provide more of a leadership role. She has become the most experienced, go-to person when no one else can figure things out. Not always by providing the answers, but also by asking the
right questions of the field operative to make them find the answer themselves.
3) The introduction of another CSI to replace the third member of the crew lost.
No doubt that will all tie in together, but the lack of those, or some viable alternatives, will be the thing hurting the show in the long run if they fail those objectives. I think there is enough in the show to carry it for a while, but before long, lacking that, you'll see a lot more retread stories with Nick in place of Sarah, Greg in place of Warrick, and none of the spark which has made the show the sustained success it has been.