ot until the clock slowly struck three.

'Thank you, gentlemen,' said the American, as he vanished between the
spring-doors. When I say vanished, I mean that word and no other,
because my men outside saw nothing of this individual then or later.
He vanished as if he had never existed, and it was some hours before
we found how this had been accomplished.

I rushed out almost on his heels, as one might say, and hurriedly
questioned my waiting men. They had all seen the tall American come
out with the greatest leisure and stroll towards the west. As he was
not the man any of them were looking for they paid no further
attention to him, as, indeed, is the custom with our Parisian force.
They have eyes for nothing but what they are sent to look for, and
this trait has its drawbacks for their superiors.

I ran up the boulevard, my whole thought intent on the diamonds and
their owner. I knew my subordinate in command of the men inside the
hall would look after the scoundrel with the pistols. A short distance
up I found the stupid fellow I had sent out, standing in a dazed
manner at the corner of the Rue Michodiere, gazing alternately down
that short street and towards the Place de l'Opera. The very fact that
he was there furnished proof that he had failed.

'Where is the American?' I demanded.

'He went down this street, sir.'

'Then why are you standing here like a fool?'

'I followed him this far, when a man came up the Rue Michodiere, and
without a word the American handed him the jewel-box, turning
instantly down the street up which the other had come. The other
jumped into a cab, and drove towards the Place de l'Opera.'

'And what did you do? Stood here like a post, I suppose?'

'I didn't know what to do, sir. It all happened in a moment.'

'Why didn't you follow the cab?'

'I didn't know which to follow, sir, and the cab was gone instantly
while I watched the American.'

'What was its number?'

'I don't know, sir.'

'You clod! Why didn't you call one of our men, whoever was nearest,
and leave him to shadow the American while you followed the cab?'

'I did shout to the nearest man, sir, but he said you told him to stay
there and watch the English lord, and even before he had spoken both
American and cabman were out of sight.'

'Was the man to whom he gave the box an American also?'

'No, sir, he was French.'

'How do you know?'

'By his appearance and the words he spoke.'

'I thought you said he d