Enter the Dragon revolves around 3 main characters; Lee, a man recruited by an agency to investigate a tournament hosted by Han, since they believe he has an Opium trade there. Roper and Williams are former army buddies since Vietnam and they enter the tournament due to different problems that they have. It's a deadly tournament they will enter on an island.
Enter the Dragon
A Shaolin martial artist travels to an island fortress to spy on an opium lord - who is also a former monk from his temple - under the guise of attending a fighting tournament.