“You were going to tell us what it is that you want us to do.”

“Yes,” replied Thorndyke. “It is quite a simple matter. We want you to look at the face of a certain person who will be shown to you, and to tell us if you recognize and can give a name to that person.”

“Not an insane person, I hope!” exclaimed Miss Dewsnep.

“No,” Thorndyke assured her, “not an insane person.”

“Nor a criminal person in custody, I trust,” added Miss Bonington.

“Certainly not,” replied Thorndyke. “In short, let me assure you that the inspection of this person need not cause you the slightest embarrassment. It will be a perfectly simple affair, as you will see. But perhaps we had better proceed at once. If you two gentlemen will follow Polton, I will conduct the ladies upstairs myself.”

On this we rose, and Miller and I followed Polton out on to the landing, where he turned and began to ascend the stairs at a slow and solemn pace, as if he were conducting a funeral. The Superintendent walked at my side and muttered as he went, being evidently in a state of bewilderment fully equal to my own.

“Now, what the blazes,” he growled, “can the Doctor be up to now? I never saw such a man for springing surprises on one. But who the deuce can he have up there?”

At the top of the second flight we came on to a landing and, proceeding along it, reached a door which Polton unlocked and opened.

“You understand, gentlemen,” he said, halting in the doorway, “that no remarks or comments are to be made until the witnesses have gone. Those were my instructions.”