While they were walking to the right, toward La Muette, in order to take a taxi, Don Luis chanced to turn his head to the road as they reached the end of the Boulevard Suchet. A man rode past them on a bicycle. Don Luis just had time to see his clean-shaven face and his glittering eyes fixed upon himself.
"Look out!" he shouted, pushing Mazeroux so suddenly that the sergeant lost his balance.
The man had stretched out his hand, armed with a revolver. A shot rang out. The bullet whistled past the ears of Don Luis, who had bobbed his head.
"After him!" he roared. "You're not hurt, Mazeroux?"
"No, Chief."
They both rushed in pursuit, shouting for assistance. But, at that early hour, there are never many people in the wide avenues of this part of the town. The man, who was making off swiftly, increased his distance, turned down the Rue Octave-Feuillet, and disappeared.
"All right, you scoundrel, I'll catch you yet!" snarled Don Luis, abandoning a vain pursuit.
"But you don't even know who he is, Chief."
"Yes, I do: it's he."
"Who?"
"The man with the ebony stick. He's cut off his beard and shaved his face, but I knew him for all that. It was the man who was taking pot-shots at us yesterday morning, from the top of his stairs on the Boulevard Richard-Wallace, the one who killed Inspector Ancenis. The blackguard! How did he know that I had spent the night at Fauville's? Have I been followed then and spied on? But by whom? And why? And how?"
Mazeroux reflected and said:
