To me this was a weak filler episode, and nothing but a string of 80's horror film cliches. Did not enjoy it.
Makes more sense at it being a second episode, but I don't understand why they switched them around - last episode actually started to suggest the story is getting somewhere - this set back the momentum.
Which is really frustrating because we're now 6 episodes into this season, and so far we have almost nothing on the supporting cast - Chas just appears, shows something, then survives a mortal wound; Zen just points at a map; and the angel pops up and tells us that a 'darkness is rising' which so far just serves as a proxy for 'a story arc is coming'.
The producers really should have kept this as episode 2, where it would have stood fine.
Meanwhile, I'm watching Agents of Shield and Arrow, where they've been developing plot from episode 1 - which makes it all the more frustrating that the producers of Constantine are still trying to find a season plot to develop - despite 6 episodes so far.
However, all my expectations are that the next episode should show something of the creative production values that crept into episodes 5&6 - more focus on supporting characters, and the human impact on everything - because these are the things that are going to set this series apart.