The world's deadliest CIA operatives are inseparable partners and best friends until they fall for the same woman. Having once helped bring down entire enemy nations, they are now employing their incomparable skills and an endless array of high-tech gadgetry against their greatest nemesis ever - each other.

The story follows a young lawyer, Arthur Kipps (Radcliffe), who is ordered to travel to a remote village and sort out a recently deceased client's papers. As he works alone in the client's isolated house, Kipps begins to uncover tragic secrets, his unease growing when he glimpses a mysterious woman dressed only in black. Receiving only silence from the locals, Kipps is forced to uncover the true identity of the Woman in Black on his own, leading to a desperate race against time when he discovers her true intent.

When Susan (Eva Green), an epidemiologist, reemerges from an affair gone sour, she encounters a peculiar patient—a Glasgow truck driver who experienced a sudden, uncontrollable crying fit. Now he is calm, but he has lost his sense of smell. Susan learns there are 11 cases like him in Glasgow, 7 in Aberdeen, 5 in Dundee, and 18 in Edinburgh. In fact, Great Britain has 100 cases, with additional ones reported in France, Belgium, Italy, and Spain, and they all appeared in the last 24 hours. Although Susan's encounter with Michael (Ewan McGregor), a local restaurant chef, holds the promise of new love, the world is about to change dramatically. People across the globe begin to suffer strange symptoms, affecting the emotions, then the senses.