Wikipédia calls this a 'roman policier', or 'detective novel', which in a way it is, only it's comedy at the same time, but 'comic detective story' doesn't hit the right button either, as this is literary fiction at the same time: I can't imagine there's an equivalent of Daniel Pennac in the Anglophone universe.
Clara, still in her teens, is marrying Clarence, who's three times older than her and the director of a model prison based on enlightened influences of such teachers as A. S. Neill and Anton Malarenko. Benjamin is very unhappy with the forthcoming marriage and in his distraction decides to part company with Queen Zabo (who is of course based on Françoise Verny, but that's a different story). And then Clarence gets savagely murdered, and all the convicts mourn his passing.
Queen Zabo's prize author is the hugely successful J. L. B(abel), an ex-minister and writer of trashy literature he labels as a new genre – littérature libéral – and who has preferred to keep his anonymity, although Queen Zabo desperately wants Benjamin to pose as the author, an offer which Benjamin takes up under certain conditions. Until, that is, he is shot through the head at a 'coming out' (as J. L. B.) speech, whereupon he falls into a coma. More killings ensue .
Benjamin's partner, the intrepid journalist Julie, tries to track down the killer, who is none other than the real J. L. B., a convict who is killed towards the end and whose organs are used in a miraculous 'kidneys-pancreas-heart-lungs' transplant, which allows Benjamin to be reborn, and of course to continue the saga. Totally unbelievable? Of course, but the 403-page trip is certainly worth it. And this volume is, like its two predecessors, translated into English by the Oulipo member Ian Monk.
My other posts on Daniel Pennac:
Daniel Pennac: Journal d'un corps
Daniel Pennac: Au bonheur des ogres | The Scapegoat
Daniel Pennac: La Fée carabine | The Fairy Gunmother