Bullet to Beijing (1995)

When long-time British Agent Harry Palmer (Sir Michael Caine) loses his job because the Cold War is over, he's promptly approached by Russian bossman Alex (Sir Michael Gambon). In St. Petersburg, Alex tells Harry of his plan for Russia's future, which is threatened because a deadly biochemical weapon called the "Red Death" has been stolen from him. He'll pay Harry handsomely to retrieve it. An ex-spy friend tips Harry off that it's being sent to Beijing by train, aboard which we begin to learn whose side everyone's really on.