Ariadne Oliver is a fictional mystery writer created by writer Agatha Christie. Mrs Oliver, who writes stories about Sven Hjerson, appears in the short story collection Parker Pyne Investigates, six novels featuring Hercule Poirot, plus the standalone novel The Pale Horse. Mrs Oliver's relationship to her fictional detective reflects that of Christie to Poirot, in that Hjerson is very popular but the writer seems to grow weary of him. From Christie's novels not much is known of Hjerson, except that he is a Finn and a vegetarian and the titles of some of his cases.