"It is," I replied, "a very tragic one—the only explanation possible is that the unfortunate gentleman whom we have just left has become insane. I am a medical man. You can see my name in the 'Medical Directory' if you look for it. I am well known in the profession. The gentleman in No. 39 has just recovered from a severe attack of typhoid fever. Until this morning he was apparently on the road to recovery. A fortnight ago he went with his wife to Cambridge to pay a short visit. They left their children at Croydon. Yesterday morning Mrs. Mainwaring heard of the illness of her eldest child and went to Croydon to see her, leaving her husband behind her at Cambridge. When she returned to Cambridge this morning he had vanished, leaving no trace behind him. We conjectured that he had come to Dover, and followed him here."

"I remember the gentleman now quite well," said the manager. "He came here quite early to-day and asked for a good bedroom, which he said he might want for a night or even two, as he was obliged to stay here until a friend joined him."

"Did he happen to tell you the name of the friend?" I inquired.

"Yes, sir, I remember the name quite well. Mr. Mainwaring said that Mr. Leigh might arrive at any moment, and that when he did he was to be shown immediately to his room."

When the manager mentioned Leigh's name Mrs. Mainwaring broke the silence which she had maintained until now.

"Walter Leigh is dead," she exclaimed.

"Good Lord, dead!" cried the manager. "Was it sudden, madam? Does the—does Mr. Mainwaring know?"

"Walter Leigh is dead," she continued. "He has been dead for many years. But ten years ago my husband stayed at this hotel and waited for Walter Leigh to join him. He had to wait here for twenty-four hours. At the end of that time Mr. Leigh arrived, and they took the next boat to Calais."

"Have you the books of the hotel of ten years back?" I asked.

"Certainly, sir."