The climax (spoilers)
A few thoughts about the second half of the last episode when things are coming to a head.
That vicar never answers his phone!
All that talk about "murder's hard and we're amatuers at it" and he thinks - I'll stop talking to my wife and answering the phone while doing this - just to make it harder
The son is a really dumb fuck like his dad , even before the co gas gets to him
How come neither of the two locked in the cellar at the end didnt immediately see that death-trap gas heater for what it was - There to kill them.
How come the son didnt turn off his phone while endlessly fretting about what to do , in order to save the limited battery.