Possible Clues:

• Sleuth whose name is French for "seller of pears"
• Fictional detective
• City breaks leading to rise for detective
• "Murder on the Orient Express" detective Hercule
• "Death on the Nile" sleuth
• Agatha Christie's Belgian sleuth
• ''. . . Orient Express'' sleuth
• Agatha Christie character who has been played by John Malkovich and David Suchet
• Solver of 33 books
• Investigator going up first round Olympic site