This was a good enough little miniseries, though it seems that it may not be this mini as more may come. I'm not sure more is needed or even wanted, but the two leads are very good and both are entertaining, so if there is more, there are a lot worse things that could happen. It's a spy thriller, along with various love stories, and it is the latter that sort of works best as the spying stuff is a bit convoluted with spies & killers popping up from anywhere & everywhere at any time, and sometimes I just stopped trying to follow the entire path and just enjoy the moment. These two genres frequently clash and this series does not lack action.
While this is not his finest moment, I've always been a fan of Ben Whishaw. He is so very talented, it amazes me how long he has mostly worked under the radar, Bond aside. His role here is a bit unique being a leading man who is a gay killer. I've always liked Keira Knightley when out of corsets. I find her to be at her best with more lighthearted fare. This isn't that, but the way it's played, it almost is and she is good here. I don't recall ever seeing her in such a kickass mode before, but she's good at it. There are a few other good performances in this most notably Ella Lily Hyland as one of the endless deadly spies, young as she may be. She is a hoot. Sarah Lancashire Is effectively ominous & mysterious while Andrew Buchan, the only person I've mentioned not killing people, as Knightley's sincerely kind, nice and honest husband is excellently gentle & warm. Just imagine a series in which the nicest person in it is an important politician! He is a true sweetheart. Much like a gay killer, you don't see this much either.
This is a bit of fun and I suppose if there is more, I might watch, but if that is two years from now, I kinda doubt it.