One of Us

There's not a whole lot of current TV that's "must watch", so I've allowed myself to watch all four episodes of One Of Us, knowing that it's  not that great, but it had a stunning cast and a great Highlands setting, even if moments seem a bit improbable. And then we get to the end of episode four and it goes totally off the rails - ludicrously unrealistic explanations and resolutions of what's been going on. From the look of it my outrage is widely shared, so how on earth has this project been able to command a massive budget for something that's ultimately so flimsy?