Obviously, I'm still a bit scarred from watching the latest adaptation of The ABC Murders, but reading the exchanges between Poirot and Japp in Death in the Clouds helps with the healing process:
Poirot’s eyes twinkled a little.
‘What you say is possible, certainly, but as regards some of your points you are in error, my friend. Those two men are not toughs—or cut-throats, as you suggest. They are on the contrary two very distinguished and learned archaeologists.’
‘Go on—you’re pulling my leg!’
‘Not at all. I know them by sight perfectly. They are M. Armand Dupont and his son, M. Jean Dupont. They have returned not long ago from conducting some very interesting excavations in Persia at a site not far from Susa.’
‘Go on!’ Japp made a grab at a passport.
‘You’re right, M. Poirot,’ he said, ‘but you must admit they don’t look up to much, do they?’
‘The world’s famous men seldom do! I myself—moi, qui vous parle—I have before now been taken for a hairdresser!’
‘You don’t say so,’ said Japp with a grin. ‘Well, let’s have a look at our distinguished archaeologists.’