A purveyor of fine art had left his shop for only an instant when he heard the crash. And discovered his plaster bust of Napoleon smashed into fragments. Mr Hudson's broken effigy is one of a batch of six, the rest of which he has sold and are now spread throughout the city -- and a similar dire fate is in store for all of "The Six Napoleons. " But criminal or lunatic, the case takes on a graver tone when there is a murder.