What director John Schlesinger has done, wisely, is to forget about the loose ends and concentrate on a series of scenes that hold us so firmly while we're watching them, that questions don't enter our minds. The movie's based on a best seller by William Goldman that was, I'm told, much tidier with its loose ends. All we know for sure is that Babe is being pursued both by Szell and by American agents. My advice to you would be to give up a good deal sooner - at the beginning of the movie, in fact - and just let 'Marathon Man' unfold. It was at about this point that I gave up trying to make sense of the plot. (If you were an ex-Nazi war criminal, wouldn't everyone be after you?) He has a relationship with the secret US agency, or at least at various points we're told he does (with this movie, we can't be certain of anything.) He's afraid the American agents will attempt to steal his diamonds, and that's why Babe's brother was killed. He's paranoid, and with some justification. When Szell's brother is killed in what can only be described as a quintessentially New York auto crash, Szell has to come out of hiding to collect the diamonds. Szell lives in hiding in South America (naturally) and has millions of dollars worth of diamonds in a New York safe-deposit box. The intrigue involves a former Nazi named Szell, played by Laurence Olivier with a certain urbane composure that makes him seem all the more ominous. And before Babe quite knows what happens, he's involved in an intrigue so labyrinthine that neither he nor the movie ever quite figures it out. A man claiming to be one of the brother's fellow operatives comes to Babe and says he needs help in setting a trap. (Isn't it a touching fantasy that there ARE jobs like that?) One day he gets killed.

Babe's brother ( Roy Scheider) works for the government, for some sort of shadowy agency that handles the dirty jobs the CIA and the FBI won't touch.

Marathon man by william goldman