I like stories that just focus on a few characters. Usually they're not done well but this is. It has enough events for pace and enough interaction (lots) to develop characters whilst slowly developing the overall story and dropping one or two shocks.
There is shrouded style that makes it so intriguing and dramatic. We never quite know what people are feeling are upto even though we probably know, but the writing is so good we doubt.
All set in a house that looks like the site they use now for modern NHS dentistry services. But even seeing that house in the start told us a lot.

By the end the weird cycles of power and manipulation are complete. We find out that even a small crack in someone's personality can be exploited by expert manipulators who's aim seems to be hot money but to change and dominate others around them to create an environment to exist as the sick people they are.