I hate to give too much away in these reviews. Especially when it's something like this that easy to give away too much about the plot line.
Simply put. You'd never expect something like this to be on CBS. It's truly exceeded any expectations and it a actually looked good in the teasers leading up to the premiere. It steals, doesn't copy from the great suspense (Hitchcock, outer limits, twilight zone, xfiles, the exorcist) and still manages to have an originality to it. It's really now the best horror/suspense show on TV.
The minute you think, "oh it's a CBS show about evil". You're going to see as it progresses, it really is all about evil and the battle against it. Your jaw will drop at how quietly they drop the hammer on a situation. Totally unexpected and totally a new classic. I hope this gets a second season!