As youll know if youve ever pushed a beaming toddler on a swing, its lovely to watch other people have fun. InBlack Doves, a new spy action thriller from the creator ofGiri/HajiandThe Lazarus Project, Keira Knightley and Ben Whishaw look like theyre having the time of their lives.Granted, thats a better time than the audience will have with this workaday and ultimately shrug off-able story, but the joy of those two running around a very Christmassy London shooting guns and having fist fights instead of delivering awards-worthy soliloquies and sighing in corsets is probably worth the six-episode time investment by itself.Knightley plays Helen (not her real name), a government minsters posh wife whos really an undercover kickass spy with gadgets, guns, and the physics-defying power to neutralise assassins with moves they dont teach at finishing school. Whishaw plays trigger man Sam, a handsome, gay, wryly funny killer-for-hire who drinks exclusively champagne, louchely calls everybody love, and sexual identity aside is a throwback to the spy-charmer likes of Harry Palmer and John Steed. Theres a bit of Emma Peel and Steed about this double-act, in fact, which is based on blood-splattered affection.Helen and Sam are colleagues in the employ of Sarah Lancashires M-like spy boss Mrs Reed. She runs the Black Doves, a mercenary agency that infiltrates the corridors of power and sells their secrets to the highest bidder. Its clearly a good earner, to judge by Mrs Reeds chauffeured cars and panoramic views of the London skyline, but doesnt pair well with a home life.Thats Sams issue more than Helens. Until her lover drags her into some shady underworld business with extraordinarily high global stakes, Helens making a good go of it as the beautiful wife of Tory defence minister Wallace Webb (Andrew Buchan) and the mother of two cherubic kids. When Helens not eavesdropping on state secrets, its all drinks receptions and school nativities and wearing Whistles dresses to fundraisers think Emma Thompsons character inLove Actuallybut with a secret gun compartment under her knicker drawer.Read more Sams life is outwardly messier. For the last few years hes been on the run from a mob boss (a ludicrously entertaining turn from gravelly voiced Kathryn Hunter) and now hes in the sights of Irish assassin Williams (Ella Lily Hyland, just as much a standout here as she was in Prime VideosFifteen Love. By rights, Hyland will one day be a bigger name than any in this cast). Theres unfinished business with an ex, Michael (Omari Douglas) and an origin story to do with his dad so patchily drawn that it could well have been introduced in the edit instead of the script.The same goes for Helens rather disinterested backstory, and for much of this plot, which revolves around the death of the Chinese ambassador and Guy Ritchie-like codes of honour among killers.If youve seen a spy thriller before, you know what youre facing: rival parties with various levels of firepower ranging from guns to nukes are all looking for the same missing thingummy. Our girl needs to get to it first to solve the mystery and take her revenge. All of that though, is just generic potato and parsnip trimmings aroundBlack Doves main roast of Ben Whishaw and Keira Knightley leaping into the Thames to avoid explosions and raiding gangster strongholds with machine guns. Along the way are rocket launchers, knife fights and enough dead bodies to fill Wembley Stadium.There are sparks of potential greatness here. Its glamorous in a London-drizzle way. The action scenes are solid and frequent. Mob boss Lenny and her pair of sardonic Irish-Welsh assassins intermittently cheer things up, while the odd witticism from the always-charming Whishaw raises a smile. Admirably, the two leads commit totally to their characters, despite them being so thinly sketched that they feel as if they didnt get beyond being brainstormed in the lift up to the pitch meeting. The bloodstained Shane Black Christmasness of it all is pretty cool too, and the soundtrack has all the festive hits.The story though, with its craftless plotting, meaningless big bad reveal, and interminable-feeling finale that spends half the runtime setting up a second season commission from a streamer increasingly unwilling to commit beyond a first, is all much more tedious. Watch it for Knightley and Whishaws star power on which basis it was almost certainly ordered by Netflix and bask in all the fun they look like theyre having. After all, its Christmas!All episodes of Black Doves are streaming now on Netflix.