Roux ran over to the telephone and called up 26-230.
"Hullo, is that you, Dr. Villebois?"
"Yes, who are you?"
"Dr. Roux is speaking. I want to know if you have any clue as to the man who injected the fluid into Professor Delapine's arm?"
"No," came the reply, "we have no actual proof as to who did it, but we believe that the would-be assassin was the same individual who set fire to Riche's room."
"What makes you think that?"
"Because by setting fire to Riche's room it would draw the people in the house upstairs, so that the fellow could not be interrupted in his ghastly work."
"I think that is quite a reasonable explanation, but what a pity the scoundrel escaped," said Roux.
"Never mind, we shall find him yet," replied Villebois.
"May we come and see you at once?" asked Roux. "It is most important."