I'd have to go back to the season where McPherson gave Artie that watch (they flashback-ed to a snippet from that)... but I can't remember what it is supposed to do either, though I'm guessing it provides a way to reset time or something.
I think many of us saw the Jinx-undercover thing coming a mile away, but less of us saw him dying as being certain, though not surprising... HOWEVER, I bet nobody saw the whole warehouse blowing up and taking Mrs Frederick along with it!
That surprised me.
Yeah baby! It's Halloween!