Most notably, this episode felt like it was balanced well between the competing strands of narrative, character and central premise that supports the show. We got a good one-off episode, with double crosses and the traditional screw ups that accompany any heist plot. We got back story seamlessly interwoven into that plot, with Topher and DeWitt having their little chat about Alpha, and DeWitt's boss making a phone appearance. We got the SFnal side, with Alpha remotely wiping Echo, and with Taffy being replicated across two dolls to try and clean up the mess. And we finally got to see Echo developing as a character.
That last was always the big concern – how would we ever care about someone who's different every week? But this episode's main arc began and ended with the focus on Echo, not a persona. They may wipe her memories (seemingly imperfectly) and they may program her, but there's something under there all the same. Echo sits with the same people every day. Echo wants to be better, to do well, and shows some strength and judgement when trapped in the vault. All the wipes are doing, maybe, is holding Echo back from becoming a real personality of her own.
I can't help but wonder where this could go if the show gets a long enough run. If Echo becomes a fully realized person, can she ever re-integrate with Caroline, her original personality? Or would recreating Caroline (presumably stored somewhere on one of Topher's cassettes) wipe out Echo? And would Echo allow that?
My only complaint with this hour of TV: How the hell did Echo and the injured techie get out the back door? I watched my tape again this morning, and I can't figure it out. If they could go out the back way, why didn't they do it earlier? That's a fairly important plot thread that got dropped there.