dark polish novel (maybe not "noir")

I mentioned a Polish novel of the 1960s in my previous post: Witold Gombrowicz's Pornografia. Pornografia has the bare bones of a "cozy" mystery plot: in the waning days of WWII, as the Nazis are retreating across occupied Poland, two friends (Witold and Frederick) travel to another friend's country house. They become fascinated by two adolescents, one the daughter of the house, the other a young orphan (a boy of about the same age as the daughter) who is staying with them. The group travels to the nearby home of the daughter's fiancé's family, and while there, the fiancé's mother (a devout Catholic) shows a strange fascination for the atheist Frederick. But in the evening, while the mother has gone to the kitchen, there are the sounds of a struggle, and the group finds the mother stabbed to death and a young interloper with stab wounds and bite wounds. The matching stories of the interloper and a kitchen maid suggest that the mother of the house attacked the interloper with a knife, and bit him savagely, before he got the knife away from her and killed her. But enough mystery surrounds the event to puzzle the most astute detective. Did she attack him? What was the boy doing in the house?
But the cozy plot disappears in a haze of another plot, this time a thriller closer to the spy genre: The group does not turn the murderer over to the police--they imprison him in the house and then return with him to the previous country house. And then the partisans demand that Witold and Frederick carry out the assasination of a traitor. From there, the plot goes further off the rails, according to a logic that is alien to either of the genre plots--a logic fully prepared for from the first pages of the novel. Whereas in the usual mystery or thriller, the fiction mimics life more or less adequately, in this novel life imitates the genres, more or less adequately. Gombrowicz is a "thesis" novelist, though of a peculiar and comic sort. He wants us to examine the structures (genres, even) through which we make sense of life as it comes at us day by day. What he is after is close to the "moral" of an existentialist novel of previous decades, such as might have been written by Camus or Sartre. Or perhaps a "nouveau roman," such as might be later written by Robbe-Grillet (who also did detective stories, of a sort). And the thesis is overlaid with the atmosphere of eroticism (and violence) implied by the novel's title--albeit a very (very) peculiar, second-hand eroticism also related to Gombrowicz's thesis (which has to do with youth versus maturity). This is an important book, one of the key accomplishments of the mid-20th century, by a writer with much to add to 20th century philosophy and art. The genre plots are not looked down upon, they are a simple structure on which to build the language and the thesis that are the writer's concern--but without which there is nothing he can say. In other words, this book is philosophy-as-story, or story-as-philosophy. There is no linear "meanning," only a portrait of our time, through the twin lenses of the mystery-thriller and Gombrowicz's own unique point of view. And, believe it or not, there's a recent movie version of the story, which I've ordered but haven't seen yet...