..or more briefly: Javert isn't relevant to the narrative except as a foil for Valjean, so Hugo had no reason to show him in Valjean-free contexts. But I do I think his whole bantering with Patron-Minette thing, and brief interactions with the Thenardier kids, do indicate that he is doing a job off-page that doesn't revolve around Valjean obsession. Is there some element of obsession at various points? Sure. But I think a one-note Javert whose entire mental life revolves around catching Valjean is a bit ludicrous, and less interesting than the alternatives.
no subject