PARADE'S END Sex on the Train

Looking for a sexy scene in Sylvia Tietjens' hotel room, which I never did find, I re-read most of Parade's End again. I couldn't help it once I got started. It's hard to put down. So the news is, there is indeed a sexual encounter between Sylvia and Christopher on a train. It's mentioned in passing in the course of a long reflection on the question whether Sylvia was already pregnant by another man at the time when she married Christopher.
No scene, no description, however. Sylvia has been seduced by a married man. She and Tietjens encounter each other on the train. End of story as far as this scene goes.
Here we have a terrific example of how movies and novels differ.
It isn't obvious, though, is it? I need to explain. I wonder if I can. One job the movie script does is to provide a few early glimpses of people who have important roles to play. (Establishing shots or introductions.) So in the novel, to English men of the "public official" class are in a train as the book opens (no, they are not having sex) and they travel to a vicarage where the vicar is a lunatic who has periodic episodes of violent, psychotic madness and therefore has to be managed by an ex-prize-fighter. At the meal, the vicar in fact has an episode of madness and has to be stopped--as it turns out, by Tietjens' friend MacMaster, who knows how to jab the lunatic in his kidney, stopping him cold, before the boxer even gets started twisting his arm behind his back. A man of action! An extremely effective fellow! And a little ruthless. Meanwhile the prospect of the lunatic episode has been prepared for by Tietjens' penetrating understanding of the entire situation. He is, in a way, a Sherlock--an English genius who takes everything in at a glance without apparently having to figure things out as the rest of us have to. So we have several characters introduced, all right, but it takes something like fifty pages to complete the intro. And we still haven't met Sylvia. But we have been given the basis and the broad outlines of the affair between masterful MacMaster and Edith Ethel Duchemin, the wife of the crazy vicar, which is an inverted mirror of the relationship, which also begins at about this time, between Tietjens and Valentine Wannop, who is the daughter of a gifted woman novelist and a suffragette. (Her mother has written the only important English novel since the eighteenth centory; however, she isn't George Eliot.) Tietjens and Valentine's affair is chaste and remains uncomnsummated for six or seven years.
Well, hey. Who's going to put up with this kind of slow narration, almost glacial, certainly gelid? (Quite a few readers, it seems.) But turning this into a counterfeit in the Upstairs/Downstairs manner is quite a stunt, much more difficult for the writer than Downton Abbey was for Julian Fellows.(Julian Fellows, incidentally, wrote the great Robert Altman sendup of this genre, Gosford Park, in which the murderer turns out to be the son.)
I guess it could turn out that Stoppard turns Parade's End into Gosford Park.