This show is a different take on the first account police responders genre which does hit the mark on many fronts, with likeable and unlikeable characters, plot and subplot, good story threads to keep you invested, redemption for questionable behaviour plus an ending.
It's more literal than cerebral, but very watchable compared to the tropes on offer.
I don't normally binge shows but I could easily while away 2 hours back to back totally absorbed in the narrative here. There was no throw away scripting or time fillers.
However, I was disappointed by the lack of exploration of Grace's mother/son relationship which seem to be there just because she needed to have some angst in her character.
I also found the ending dissatisfying given the ease with which the intelligence services capitulated after all the talk of the European magnitude of their operation. That just wouldn't happen. Not least a constable interfering with a CID suspect who had more than adequate legal council.
For these reasons I gave it 3/5.
I don't feel there is enough substance to justify a season2.