It's a little late to be mentioning this, but Hercule Poirot is the greatest villain of Agatha Christie's world (and hence ours, what with the way that fiction interpenetrates). Poirot is inseparable from murder, just as the goddess of the hunt, Diana, is one with the stag. A murder need not have already occurred — Poirot is there, his very presence guaranteeing death. His investigations have nothing to do with serving justice. Let's take an example at random: Death on the Nile
. One single, purposeful murder unnecessarily multiplies into five
deaths, wholly due to Poirot's egomaniacal investigation. It's inconceivable that five deaths with Poirot's bloody "case closed" stamp are preferable to an unsolved mystery with a single victim. When Poirot finally gathers his (surviving) suspects to endure an interminable blathering of self-congratulation, he never addresses the elephant in the room — the fact that the world would be an infinitely safer place if he were to leave well enough alone. P.S. Poirot is obsessed with motives, as if anyone with a motive possesses, by definition, a criminal mind and the capacity for murder. His presumption that everyone on earth is capable of cold-blooded killing says far more about Poirot's own rotten soul than it does about the rest of humanity.