Jack, our hero, who has much bushier than regulation eyebrows, has a helicopter crash in Afghanistan and sustains a leg-threatening injury. While recuperating he falls for Keira Knightley, who weans him off pain killers and ends up co-habiting with him. He is recruited by Kevin Costner (looking quite crusty) to join the CIA, and ten years later, after completing his PhD, he is undercover in a financial company when he spots that the Russians are up to something - they seem to be trying to undermine the economy of the United States of America in some petulant attempt to get revenge for some pipeline deal which didn't work out for them.
Jack has to go to Moscow. There, he drowns a bad guy in his opulent hotel suite and has to make a run for it into the streets of the city. He meets his contact (Kevin Costner), who has stolen a spaniel as part of his cover for being in the park at night, and he has a heart-to-heart about the first time he killed someone on CIA duty. It was an innocent bystander, he says, and to make it worse, it was a woman, and all she did was approach him from behind unexpectedly. A poignant memory, no doubt, and these kinds of things are what CIA operatives have to live with.
Anyway, Jack sets up an appointment with Kenneth Brannagh, the evil Russian who is all set to send America into a bit of a depression the like of which is unthinkable. After an awkward meeting, Jack has to set up a date with this horrid man, and he has to bring his girlfriend with him. She will have to keep him busy while Jack goes off with his laptop, breaks into a swish office and gets something vital downloaded. (There are Americans with computers and black executive four-by-fours all over moscow, it seems.) Keira Knightly gets kidnapped, there is a car chase, the Russian bloke threatens to put an economy lightbulb in her mouth and make it explode somehow - something which would effect her dental health and her looks. Jack is furious, but saves Keira. They all go back to the States. Well, the rest is similarly silly and cliched.