"How did that help you?"

"It was all-important. When a woman thinks that her house is on fire, her instinct is at once to rush to the thing which she values most. It is a perfectly overpowering impulse, and I have more than once taken advantage of it. In the case of the Darlington substitution scandal it was of use to me, and also in the Arnsworth Castle business. A married woman grabs at her baby; an unmarried one reaches for her jewel-box. Now it was clear to me that our lady of to-day had nothing in the house more precious to her than what we are in quest of. She would rush to secure it. The alarm of fire was admirably done. The smoke and shouting were enough to shake nerves of steel. She responded beautifully. The photograph is in a recess behind a sliding panel just above the right bell-pull. She was there in an instant, and I caught a glimpse of it as she half-drew it out. When I cried out that it was a false alarm, she replaced it, glanced at the rocket, rushed from the room, and I have not seen her since. I rose, and, making my excuses, escaped from the house. I hesitated whether to attempt to secure the photograph at once; but the coachman had come in, and as he was watching me narrowly it seemed safer to wait. A little over-precipitance may ruin all."

"And now?" I asked.

"Our quest is practically finished. I shall call with the King to-morrow, and with you, if you care to come with us. We will be shown into the sitting-room to wait for the lady; but it is probable that when she comes she may find neither us nor the photograph. It might be a satisfaction to his Majesty to regain it with his own hands."

"And when will you call?"

"At eight in the morning. She will not be up, so that we shall have a clear field. Besides, we must be prompt, for this marriage may mean a complete change in her life and habits. I must wire to the King without delay."

We had reached Baker Street and had stopped at the door. He was searching his pockets for the key when someone passing said:

"Good-night, Mister Sherlock Holmes."

There were several people on the pavement at the time, but the greeting appeared to come from a slim youth in an ulster who had hurried by.

"I've heard that voice before," said Holmes, staring down the dimly lit street. "Now, I wonder who the deuce that could have been."