What part was she playing in the case?

People came in and were taken to the patients whom they had called to see. Others went out. There were also sisters moving silently to and fro and nurses dressed in their long white overalls belted at the waist.

"We're not doing any good here, Chief," whispered Mazeroux.

"What's your hurry? Is your sweetheart waiting for you?"

"We're wasting our time."

"I'm not wasting mine. The meeting at the Prefect's is not till five."

"What did you say? You're joking, Chief! You surely don't intend to go to it."

"Why not?"

"Why not? Well, the warrant--"

"The warrant? A sc.r.a.p of paper!"

"A sc.r.a.p of paper which will become a serious matter if you force the police to act. Your presence will be looked upon as a provocation--"

"And my absence as a confession. A gentleman who comes into a hundred millions does not lie low on the day of the windfall. So I must attend that meeting, lest I should forfeit my claim. And attend it I will."

"Chief!"

A stifled cry was heard in front of them; and a woman, a nurse, who was pa.s.sing through the room, at once started running, lifted a curtain, and disappeared.

Don Luis rose, hesitating, not knowing what to do. Then, after four or five seconds of indecision, he suddenly rushed to the curtain and down a corridor, came up against a large, leather-padded door which had just closed, and wasted more time in stupidly fumbling at it with shaking hands.

When he had opened it, he found himself at the foot of a back staircase.

Should he go up it? On the right, the same staircase ran down to the bas.e.m.e.nt. He went down it, entered a kitchen and, seizing hold of the cook, said to her, in an angry voice:

"Has a nurse just gone out this way?"

"Do you mean Nurse Gertrude, the new one?"

"Yes, yes, quick! she's wanted upstairs."

"Who wants her?"

"Oh, hang it all, can't you tell me which way she went?"

"Through that door over there."

Don Luis darted away, crossed a little hall, and rushed out on to the Avenue des Ternes.

"Well, here's a pretty race!" cried Mazeroux, joining him.

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 Leva.s.seur?" 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 Leva.s.seur'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 Leva.s.seur 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 Leva.s.seur under her nurse's uniform. She cast round her eyes as if to make sure that she was not being followed, and then took a cab and drove down the boulevard and the Rue de la Pepiniere, to the Gare Saint-Lazare.

Don Luis saw her from a distance climbing the steps that run up from the Cour de Rome; and, on following her, caught sight of her again at the ticket office at the end of the waiting hall.

"Quick, Mazeroux!" he said. "Get out your detective card and ask the clerk what ticket she's taken. Run, before another pa.s.senger comes."

Mazeroux hurried and questioned the ticket clerk and returned:

"Second cla.s.s for Rouen."

"Take one for yourself."

Mazeroux did so. They found that there was an express due to start in a minute. When they reached the platform Florence was stepping into a compartment in the middle of the train.

The engine whistled.

"Get in," said Don Luis, hiding himself as best he could. "Telegraph to me from Rouen; and I'll join you this evening. Above all, keep your eyes on her. Don't let her slip between your fingers. She's very clever, you know."

"But why don't you come yourself, Chief? It would be much better--"

"Out of the question. The train doesn't stop before Rouen; and I couldn't be back till this evening. The meeting at the Prefect's is at five o'clock."

"And you insist on going?"

"More than ever. There, jump in!"

He pushed him into one of the end carriages. The train started and soon disappeared in the tunnel.