Quite enjoyed it, to be honest. Not keen on the intro song, at all, superficial, droning, pish. Wasn't liking the songs played throught the episode, either. Those are minor complaints, though. As for the actual episode, I'm interested in where it is going, quite like the cast, so far.
Regarding the supernatural, stuff.
[Show spoiler]Those scientists have discovered some old frozen microbe that has made its way into the water, which is causing hallucinations.
I reckon.