US viewers can see it on BBC America's website. I assume UK viewers know they can view it on the BBC's website. Other countries, you'll have to see which site works for you. (Or find a torrent.)
My thoughts behind the cut.
Okay, I like plots that have to do with kids being creepy or whatnot, as long as it's not a kid's show, then the plots get old. But what the heck? It seems we don't have any new team members in this trailer. And there's a specific reference that indicates they're not just left out of the trailer, but not in at least part of the series. Now, I don't need it to be Martha and/or Mickey, but it would be nice. I do want more than a team of three though. Especially as I'm lukewarm to Gwen. If they think this 'love triangle' thing is going to fly solo, I think they're wrong.