“There was a ball, was there?” Francis asked.

“Without a doubt,” the detective replied. “It was given by a Miss Clara Bultiwell. She happens to remember urging Miss Hyslop to come on as early as possible.”

“So that's that,” Francis observed.

“Just so, Mr. Ledsam,” the detective murmured.

They were walking along the Mall now, eastwards. The detective, who seemed to have been just a saunterer, had accommodated himself to Francis' destination.

“Let me see, there was nothing stolen from the young man's person, was there?” Francis asked presently.

“Apparently nothing at all, sir.”

“And I gather that you have made every possible enquiry as to the young man's relations with his friends?”

“So far as one can learn, sir, they seem to have been perfectly amicable.”

“Of course,” Francis remarked presently, “this may have been quite a purposeless affair. The deed may have been committed by a man who was practically a lunatic, without any motive or reason whatever.”