The Prince nodded amiably. He seemed in no way discomposed.

"I feel convinced," he said, "that you are right. I agree with you.
I believe that Inspector Jacks has had that idea for some little time
now."

The doctor gripped the sides of his chair and stared at this man who
discussed a matter so terrible with calm and perfect ease.

"Yes, I have felt that more than once," the Prince continued. "My
presence upon the spot at that precise moment with injuries which had to
be explained somehow or other, was, without doubt, unfortunate."

The two men sat for several moments without further speech. The doctor's
features seemed to reflect something of the horror which he undoubtedly
felt. The Prince appeared only a trifle bored.

"So that is why," the former exclaimed hoarsely, "I have been appointed
your physician in chief!"

"I had given you the credit, my dear doctor," the Prince said smoothly,
"of having arrived at that decision some time ago. To a man of your
perceptions there can scarcely have been any question about it at all.
Besides, even Princes, you know, do not give fees of a thousand guineas
for nothing."

Dr. Whiles rose slowly to his feet.

"You know the secret of that murder!" he declared.

"Why ask me?" the Prince answered. "If I tell you that I do, you may
find conscientious scruples about remaining here. A man is not bound,
you know, to give himself away. Make the best of things, and do not try
to see too far."

The doctor was looking a little shaken.

"If you were mixed up in that affair," he said, "and if I remain here
when my evidence is needed, I become an accomplice."

"Only if you remain here voluntarily," the Prince reminded him
cheerfully. "Remember that and be comforted. No effort that you could
make now would bring you into touch with Mr. Inspector Jacks until I am
quite prepared. So you see, my dear doctor, that you have nothing with
which to reproach yourself. I will not insult you," he continued, "by
suggesting that a reward of fifty pounds could possibly have influenced
your attitude. If you have suffered your mind to dwell upon it for a
single moment, try and remember the relative unimportance of such an
amount when compared with a thousand guineas."

The doctor moved to the window and back again.

"Supposing," he said, "I decline to remain here? Supposing I say that,
believing you now to have a guilty knowledge of this murder, I repudiate
our bargain? Supposing I say that