Jonathan Pine, a spy, plants himself into the inner circle of a charismatic wealthy arms dealer, travelling around the world with him trying to get enough dirt on his dealings to take him down. Meanwhile, his bosses at the intelligence services in the UK and USA are waging their own internal battles.
Some back story for Black Widow (Scarlett Johansson), from the Avengers. We see her grow up with two Russian spy foster parents in the USA (David Harbour, Rachel Weisz). When their mission is over, the ‘family’ are split up. Years later her ‘sister’ (Florence Pugh) reaches out for her help tracking down a villain (Ray Winstone). Cue swishy fighting and explosions.