Arthur Conan Doyle’s ‚The Hound of the Baskervilles‘, Georges Simenon’s ‚Le chien jaune‘ and Friedrich Dürrenmatt’s ‚Der Richter und sein Henker‘ stand for specific variants of the detective novel, and, moreover, they draw on quite different national literary traditions. All three, however, are haunted by a ‚beast dog‘. This is precisely the starting point of the present comparative reading. It tries to display the ways in which the beast dogs, interplaying with countless animal comparisons and metaphors, refer the three texts to a ‚shared‘ discursive context: All three vary the figure of thought of the ‚bête humaine‘, a model that fascinated cultural critics from the late 19th until well into the 20th century. Surprisingly, the novels endow not only suspects and criminals with ‚primitive‘ animal features, but also the investigators Holmes, Maigret and Bärlach. In other words: In the examined texts – doubtlessly belonging to the classics of crime literature –, the beast dog contributes to questioning an opposition which is purportedly constitutive of the genre itself.