If you can completely withdraw any sense of realism,.then this is a good watch.
While the premise is Dexter-eaque, the delivery isn't quite at the standard we would expect from ITV.
Some of the characters are excellently played, but watching Elizabeth Bancroft scheme and murder he way through a 30-year career in the police, I can't help but sometimes shout at the screen in frustration at her colleagues who apparently, are competent and in some cases, exceptional .
It's worth a watch, but there are better.