Surprise Beginnings: Volume 4 of Parade's End

Not surprised that volume 4 of Ford Madox Ford's Parade's End opens up in the North Country at or near Tietjens's family estate, Groby - throughout the war years that the first three volumes span he had been desultorily dreaming of returning to that estate, and at other times about running an antiques shop on the south coast - but I was surprised that the volume, Last Post, opens by centering on Tietjens's brother, Mark. We find Mark T living in a kind of open-air shed somewhere on his expansive grounds, and he has been immobile and confined to a chair or bed and unable - or perhaps unwilling - to speak; he is tended to by a very competent but not well-educated groundskeeper - giving FMF occasion for his typical class condescension - and by his mistress-partner of long standing (I don't think they're married, not sure though), a French woman who dreams of retiring to her homeland, well taken care of by whatever legacy Mark T leaves her; she's incredibly voluble, the opposite of T - this was true of their life even during and before the war - and discourses on all sorts of subjects, while he has one interest only, horse races - he reads the racing pages in the papers on some reading contraption she sets up for him. The kicker of these first two chapters is that all think that MT has suffered a stroke and cannot move or talk - various docs have seen him, though the only one his "wife" trusts is the French one - but in the sections told from MT's POV he indicates that he is perfectly capable of moving and speaking but has vowed not to - this is not really credible, either it's his self-deception of a symbolism of some kind - since the Armistice, when the allies decided to allow the Germans to retreat across France w/out pursuit. Not sure why FMF spends so much time here on two characters who had either no role in first 3 volumes or very little - and there is indication that Tietjens and his partner, Valentine Wannop, will visit Mark T - who, btw, as best I can recall, deprived T of part of the father's legacy? Not sure about the details, from back in volume 2. This section is more FMF tour de force interior monologue, clearly in the tradition of Woolf and Joyce and even Faulkner, though I'm not sure if he had read Faulkner at that stage of his life - does remind me of sections of such pieces as The Bear w/ very long interior monologues and little outside information or context to hold our hands as we move along on the journey - very demanding of the reader, and a very intense reading experience if you can enter the character's mind.