Intrepid Parisian reporter Ric Hochet finds himself on home turf when a sudden increase in crime in the capital is linked with a surprise publishing phenomenon: a "how-to" guide to murder... An editorial miscalculation, or malicious hoax? Ric and Nadine's investigation takes them to a small town in Belgium where they discover that the Marabout publishing company is not exactly the big, happy family its founder and manager Gerard André believes it to be. But who is really behind the mysterious guide? And are they guilty of murder?