I rose and locked the door. My visitor sank with a groan into my
chair.

"'Why did you do that?' he stammered, as I turned the key in the lock.

"'To keep my Scotch whiskey from evaporating,' I said, dryly. 'Now, my
lord,' I added, 'it will pay your Grace to let me have your hat. I know
who you are. You are the Duke of Brokedale. The Duchess of Brokedale has
lost a valuable tiara of diamonds, and you have not lost your watch.
Somebody has stolen the diamonds, and it may be that somewhere there is a
Bunker who has lost such a watch as I have described. The queer part of it
all is,' I continued, handing him the decanter, and taking a couple of
loaded six-shooters out of my escritoire--'the queer part of it all is
that I have the watch and you have the tiara. We'll swap the swag. Hand
over the bauble, please.'

"'But--' he began.

"'We won't have any butting, your Grace,' said I. 'I'll give you the
watch, and you needn't mind the L200; and you must give me the tiara, or
I'll accompany you forthwith to the police, and have a search made of your
hat. It won't pay you to defy me. Give it up.'

"He gave up the hat at once, and, as I suspected, there lay the tiara,
snugly stowed away behind the head-band.

"'You are a great fellow.' said I, as I held the tiara up to the light and
watched with pleasure the flashing brilliance of its gems.

"'I beg you'll not expose me,' he moaned. 'I was driven to it by
necessity.'

"'Not I,' I replied. 'As long as you play fair it will be all right. I'm
not going to keep this thing. I'm not married, and so have no use for such
a trifle; but what I do intend is simply to wait until your wife retains
me to find it, and then I'll find it and get the reward. If you keep
perfectly still, I'll have it found in such a fashion that you'll never be
suspected. If, on the other hand, you say a word about to-night's events,
I'll hand you over to the police.'

"'Humph!' he said. 'You couldn't prove a case against me.'

"'I can prove any case against anybody,' I retorted. 'If you don't believe
it, read my book,' I added, and I handed him a copy of my memoirs.

"'I've read it,' he answered, 'and I ought to have known better than to
come here. I thought you were only a literary success.' And with a
deep-drawn sigh he took the watch and went out. Ten days later I was
retained by the Duchess, and after a pretended search of ten days more I
found the tiara, restored it to the noble lady, and received