Best of an island is once you get there - you can't go any farther...you've come to the end of things... - Agatha Christie

“Ah!” Poirot shook his forefinger so fiercely at me that I quailed before it. “Beware! Peril to the detective who says: ‘It is so small — it does not matter. It will not agree. I will forget it.’ That way lies confusion! Everything matters.”

“You have been to the Riviera before, Georges?” said Poirot to his valet the following morning. George was an intensely English, rather wooden-faced individual. “Yes, sir. I was here two years ago when I was in the service of Lord Edward Frampton.” “And to-day,” murmured his master, “you are here with Hercule Poirot. How one mounts in the world!”

"But then, how do you know?"
"Because I am Hercule Poirot I do not need to be told."