On the trail of Agatha Christie's enduring appeal

Ninety years after the publication of her first novel, The Mysterious Affair at Styles, Agatha Christie is as popular as ever. A case for Lucy Mangan to investigate Photograph: Mark Thomas

The Agatha Christie festival takes place once a year in Torquay, Devonshire, kicking off with a traditional fete, complete with wooden hula hoops and splat-the-rat contests
Photograph: Jim Wileman

An Agatha-only book stall, with a choice selection of some of her 80 novels Photograph: Jim Wileman

Local Rotary Club members doing the Charleston Photograph: Jim Wileman

Martin Gaisford, who plays Hercule Poirot for a living, says that Christie's Belgian detective is recognised all over the world. 'I've gone a few times to the World Travel Fair as Poirot,' he says, 'and you can go past some really obscure country's stall and they'll shout out his name' Photograph: Jim Wileman

There is all kinds of Christie merchandise and memorabilia, coveted by the most avid of fans, including these rather natty deckchairs Photograph: Jim Wileman

One well-dressed punter fishes for ducks ... or clues Photograph: Jim Wileman

Emma Klausner, festival attendee and fan: 'I've read about 10 or 15 of the books and watched every Marple and Poirot, but I just love the 20s and 30s. It would be lovely to go back in time and see that era. It was just so elegant, so stylish' Photograph: Jim Wileman

Lucy Mangan gets into the swing of things Photograph: Jim Wileman

A festivalgoer finds another use for one of Christie's page-turners Photograph: Jim Wileman