I've been drawn into this in spite of myself. The acting is fantastic and the locations/clothes/decor is out and out eye candy. However it is so so slow! I'm more used to HBO dramas which could pack an hour of this show into 15 minutes, just not much really happens. There are only so many 'mildly malicious' looks across the office floor I'm interested in seeing.
I also feel like it has the potential to be really thrilling and interesting (yy to pp's Sophie Hannah comparisons) but also it could just go down the exact route we expect (e.g. Paula is boffing Kay's DH and wants Ellen's job/life/whatever). Like Doctor Foster did - no twist!!
If there is a clever twist, at the current pace I'm not sure they'll manage to resolve it in one more episode.
A few more theories: Paula's house isn't really hers, they're just squatting (hence they've hardly managed any renovations); Paula knows David/Kay/Ellen from university days (which, crucially, pre-date Ellen's mental breakdown?) and has a much older vendetta than we realise. Or maybe she isn't actually a qualified architect at all! Maybe she is actually Georgia. Or something. I think Georgia definitely thought that Ellen WAS Paula - hence being so afraid of her and telling her she couldn't call her 'again' - she definitely seemed to be referring to something we haven't seen ourselves.
I'd love it if there was a MASSIVE twist, like someone is pretending to be someone else 100% (maybe the Facebook thing was a clue). Maybe Georgia took over Paula's life or something else.
Also think the PP saying Ellen's husband is dodgy are onto something. He's so lovely though!
Kay's husband seems MASSIVELY dodgy.
The thing about Kay's final phone call to Ellen seems to me that if it was about Paula, there wasn't a massive basis for that as all we saw was her looking across the office at her, like once. Whereas the Ellen-Kay-Kay's husband triangle seems a little weird and toxic and also as far as we know is much older/more long term. The 'I've finally realised what's been going on' thing sounds more likely to refer to that than to the more recent Paula thing (which hardly seemed to concern Kay in the bits we've seen).