Michael Caine and Laurence Olivier are the only actors on screen for the duration of this film in a back and fourth, dialogue heavy, game of murder and misdirection between two  resentful and competitive characters. Lots if good while delivered lines and fluid directing. Realistic, direct, and dynamic ethnocentrism is written well into both the characters frame of mind and personality. One thing I can't stand is having to look at all the nasty automatons though.