If your heart sinks at the prospect of a thriller series starring Keira Knightley as a highly trained undercover agent with unfeasible martial skills, join the club. The reason I was drawn to Black Doves was when I realised it had been written by that master of tongue-in-cheek, ultraviolent, popcorn TV, Joe Barton (Giri/Haji). However disappointing Knightley might be, I thought, Barton's mordant humour, surreal imagination and sassy dialogue would more than ease the pain.
Actually, though, Knightley isn't at all bad - especially when she is playing her 'cover' character, Helen Webb, the trad wife of defence secretary and probable future prime minister Wallace Webb (Andrew Buchan). I found her domestic scenes - making Christmas decorations with her young kids, being glamorous at the office party, dealing with the nanny, smilingly warding off the pretty, potential love rival, getting changed etc - so utterly convincing, it was as if all her really annoying performances had never happened (like that of the totally made up woman in The Imitation Game, who was far cleverer than all the male codebreakers at Bletchley).
What she's slightly less good at - and it's hardly her fault: it's an impossible part - is persuading us that despite those stick-thin wrists, slender hands and frangible features she could take any amount of punishment in a brutal fist fight before finishing you off with a fruit knife. Of course she couldn't. Nor could any woman of Knightley's physique. It's a trope which was ticklish, cute and quite original when La Femme Nikita came out in 1990, but 34 years on its charm has long since staled.
Just suppose we're to accept that Knightley has mastered these skills.