As I've said before, these end of season episodes are so contrived that they have no center to hold them. While the conclusion of this one is comfortably in the canon, it offers us nothing new. It opens up a series of unanswered questions. There are so many tricks to dealing with time travel. The immutability of time creates a situation where going back just creates too many questions. It's a nice idea, but like so many efforts in the past, it doesn't wash. I was amused that the best performance was by long time bit player on CSI, Wally Langham. I also wonder why they didn't use the budget for the big stars to create a really top notch episode. All that aside, I haven't watched the seventh season but hope it fares better.