Roger's heart sank. Horrible as it was to contemplate the thought of the crime committed in their midst, it was to him infinitely worse to think of Esther as mentally unbalanced.
"Have you noticed anything yourself which you would regard as a suspicious symptom, doctor?" he inquired with difficulty.
"Only her violent antipathy to Dr. Sartorius. I should consider that rather a bad sign. It is the sort of thing these subjects are prone to, monsieur," and the little man shook his head disparagingly.
Roger risked one more question, dreading the answer.
"How can we find out about her? You say she will have to be studied?"
"Very probably, monsieur. There are certain tests. I should suggest that if the young woman is someone in whom you are particularly interested"—he gave a tactful cough which Roger understood well—"the best thing you can do is to place her for a few weeks in a quiet sanatorium. There is one near Grasse; either Dr. Sartorius or I could arrange it, for you."
"I see, doctor. Well, we will think about it."
He watched the little man depart, grimly resolved never to let Esther be placed in a sanatorium, no matter what happened. Sartorius himself had mentioned the quiet place near Grasse. That fact alone was enough to decide him against it. He was alone now with Esther. A few minutes before he had persuaded his aunt to go to her room and try to sleep. She had demurred at first, but he had firmly led her to her door.
"I'll go if you insist," she gave in at last. "But you're so far from well yourself, it will be a great strain on you to sit up all night."
"Nonsense; this business has made me forget all about myself. If you insist on sharing watches, I will call you early in the morning."