“I gave him the coin, for I was now profoundly puzzled, and he went out.  He was gone perhaps twenty minutes, and when he came in he had a bucket of water.  But he had evidently been thinking on the way, for he set the bucket down carefully, wiped his hands on his canvas breeches, and began to speak, with a little apologetic whimper in his voice.

“`Now look here, Governor,’ he said, `I’m a-goin’ to talk turkey; do I git the five thousand if I find this stuff ?’

“`Surely,’ I answered him.

“`An’ there’ll be no monkeyin’, Governor; you’ll take me down to a bank yourself an’ put the money in my hand?’

“`I promise you that,’ I assured him.

“But he was not entirely quiet in his mind about it.  He shifted uneasily from one foot to the other, and his soft rubber nose worked.

“`Now, Governor,’ he said, `I’m leery about jokers — I gotta be.  I don’t want any string to this money.  If I git it I want to go and blow it in.  I don’t want you to hand me a roll an’ then start any reformin’ stunt — a-holdin’ of it in trust an’ a probation officer a-pussyfootin’ me, or any funny business.  I want the wad an’ a clear road to the bright lights, with no word passed along to pinch me.  Do I git it?’

“`It’s a trade!’ I said.

“`O.  K.,’ he answered, and he took up the bucket.  He began at the door and poured the water carefully on the hard tramped earth.  When the bucket was empty he brought another and another.  Finally about midway of the floor space he stopped.

“`Here it is!’ he said.

“I was following beside him, but I saw nothing to justify his words.

“`Why do you think the plates are buried here?’ I said.

“`Look at the air bubbles comin’ up, Governor,’ he answered.”

Walker stopped, then he added: 

“It’s a thing which I did not know until that moment, but it’s the truth.  If hard-packed earth is dug up and repacked air gets into it, and if one pours water on the place air bubbles will come up.”

He did not go on, and I flung at him the big query in his story.

“And you found the plates there?”

“Yes, Sir Henry,” he replied, “in the false bottom of an old steamer trunk.”

“And the hobo got the money?”

“Certainly,” he answered.  “I put it into his hand, and let him go with it, as I promised.”

Again he was silent, and I turned toward him in astonishment.

“Then,” I said, “why did you begin this story by saying the hobo faked you?  I don’t see the fake; he found the plates and he was entitled to the reward.”

Walker put his hand into his pocket, took out a leather case, selected a paper from among its contents and handed it to me.  “I didn’t see the fake either,” he said, “until I got this letter.”

I unfolded the letter carefully.  It was neatly written in a hand like copper plate and dated Buenos Aires.