“Very well, madame. No doubt I will be better to-morrow.”

On the morrow Margot was worse, and within two days she had to ask the concierge to call the doctor. He looked a little puzzled when he examined her, but prescribed a treatment, and said he would call again later. On his third visit a curious red rash covered her.

“Hum!” he said, “I’m afraid it’s scarlet fever.”

On his next visit he was still more puzzled and asked her many searching questions. He went away looking very serious indeed. All that day Margot waited, anxious and unhappy. The red spots developed in the strangest manner. When the doctor returned late at night and saw them something like a shudder passed over him. He drew on his gloves hastily.

“There’s nothing to do, mademoiselle. I am going to the Institute Pasteur. They will send an ambulance first thing in the morning. You are lucky that I can get you in. You will get better attention there than anywhere else.”

“What’s the matter?”

“You mustn’t worry. It is most unfortunate. It must have been those clothes from the laundry. I am going straight to the police. Please wait patiently till the ambulance comes. Don’t be alarmed.”

“But, doctor, tell me, for the love of God! What have I got?”

He looked around as if to be sure there were no listeners, then said slowly:

“My poor girl, I may be mistaken but I think it’s....”