Who is greatest Hercule Poirot of them all?
First, last and forever, there is the mustache. It's spelled "mustache" according to the Associated Press and therefore also to the Chicago Tribune. But in Agatha Christie's stories featuring her most famous and fastidious creation, the Belgian detective Hercule Poirot, now 103 years old, the spelling favors "moustache" and very often "moustaches," plural.