"Excellent," said the wily Boyne. "Let it be so, as you say. We are enemies. So go back to Upper Brook Street and find madame. Go and try to blackmail her. Meanwhile I shall call the next constable I meet and give you both in charge as undesirable foreigners."
The Frenchman, however, only laughed in his face, saying:
"Yes, do so, mon cher ami! I fancy you would regret such an action. But we are enemies, and at any rate, I intend to see madame, your friend."
"You want money, eh?" growled Boyne, as they stood together on the kerb.
"Perhaps we do—and perhaps we do not. It all depends upon your attitude—and madame's!" he replied, with mock politeness. "The mystery of the death of Monsieur Martin requires elucidating, and Céline can do that—when it becomes necessary."
"I don't understand you," Boyne said. "What about the old man's death?"
"Now, that's quite enough!" cried Galtier, in impatient anger. "It's no use you, of all men, pleading ignorance, Mr. Bennett. Céline has already had a little present from madame to keep a still tongue, and——"
"And you want a bit more, eh?" asked Boyne bluntly.
"No. That's just where you are mistaken, my friend!" was the Frenchman's reply. "Monsieur Martin died in mysterious circumstances, of which both madame and yourself are well aware, and it is but right that the police should know the truth, otherwise we may have other people dying in a similar manner!"
Those last words of his caused Boyne to wince. For what reason, if not with the object of blackmail, had Henri Galtier and Céline Ténot come to London and tracked them down?