SEASON FINALE: My head spins, trying to figure out, with Syfy and USA shows, what’s a season finale, a midseason finale, or just another episode. Last week I got it wrong, prematurely identifying that night’s episode as the season ender. It’s actually tonight. I think. And if it’s the episode I think I previewed, it’s got a very clever ending, which puts our heroes on either side of an impenetrable barrier. Sort of like Under the Dome.