Dans la diagonale is written in a truncated, telegraphic fashion with verbs usually omitted, sometimes with many pages with no sentence or paragraph breaks, just strings of phrases making very little sense. In a word, it's a mess, and the lack of reviews of the novel are surely testimony to its almost total failure to engage the reader.
The story, such as it is: the narrator, who only uses the first person in the opening section to reply to a few questions, and his name appears to be Teddy. To the narrator's horror, he is hailed in the street by an old schoolmate Jacques, who invites him to a party he's having with his wife Anabelle. The narrator feels obliged to go and hitches there, subjecting the reader to the comments of the various drivers made on his way.
When the narrator arrives the scene seems to be something out of a Buñuel film, with gluttony, heavy drinking and sexual lust coming to the fore: so could this be a satire on the bourgeoisie, with added criticisms of the way people from the south of France speak in extra syllables, or others denote expressions in 'speech marks' at the side of their ears, etc? If so the joke wears thin after a while and the reader gets sick of the constant repetition. This is all played out against a backdrop of TV footage of the war on Iraq and music from Alain Bashung, The Strokes and Green Day but not (as one guest would have liked), Édith Piaf.
And the party develops into some kind of orgy and the narrator is accused of raping Annabelle, to which he won't admit. I could go on but let's just say that François Bégaudeau is very far from being James Joyce. Not a disaster novel but a disastrous one. 'Je m'en lave les mains'.*
*Alain Bashung, 'La nuit je mens'.