Don Luis stood scanning the avenue. A motor bus was starting on the little square hard by, the Place Saint-Ferdinand.
"She's inside it," he declared. "This time, I shan't let her go."
He hailed a taxi.
"Follow that motor bus, driver, at fifty yards' distance."
"Is it Florence Levasseur?" asked Mazeroux.
"Yes."
"A nice thing!" growled the sergeant. And, yielding to a sudden outburst: "But, look here, Chief, don't you see? Surely you're not as blind as all that!"
Don Luis made no reply.
"But, Chief, Florence Levasseur's presence in the nursing-home proves as clearly as A B C that it was she who told the manservant to bring me that threatening letter for you! There's not a doubt about it: Florence Levasseur is managing the whole business.
"You know it as well as I do. Confess! It's possible that, during the last ten days, you've brought yourself, for love of that woman, to look upon her as innocent in spite of the overwhelming proofs against her. But to-day the truth hits you in the eye. I feel it, I'm sure of it. Isn't it so, Chief? I'm right, am I not? You see it for yourself?"
This time Don Luis did not protest. With a drawn face and set eyes he watched the motor bus, which at that moment was standing still at the corner of the Boulevard Haussmann.
"Stop!" he shouted to the driver.
The girl alighted. It was easy to recognize Florence
