In Inception, Dom Cobb tests the limits of reality by travelling into dreams. In Tenant, also written and directed by Christopher Nolan, a CIA agent (John David Washington) travels through time to complete a special mission: to prevent the onset of World War III. What's the cause behind the potential world war? Russian oligarch Andrei Sator (Kenneth Branagh) is suffering from cancer and dying. Because he is a billionaire, Sator believes that he should be exempt from suffering and wants the rest of the world to suffer alongside him, and he decides to create a nuclear bomb to wipe out all of humanity.