You've almost seen this man at work....

You've understood him.

Isn't a man like this, I ask you, capable of anything ?" "He is," said the Duke, with conviction.
"Well, then," said Guerchard.
"Perhaps you're right," said the Duke.
Guerchard turned to Dieusy and said, in a quieter voice, "And when the scavenger had picked up the cigarette, did he follow the motorist ?" "Yes, he followed him for about a hundred yards.

He went down into Sureau Street, and turned westwards.

Then a motor-car came along; he got into it, and went off." "What kind of a motor-car ?" said Guerchard.
"A big car, and dark red in colour," said Dieusy.
"The Limousine!" cried the Duke.
"That's all I've got so far, sir," said Dieusy.
"Well, off you go," said Guerchard.