her back again.

The Bradys would hardly have touched the case if it had not been that Mr. Butler occupied a government position at Albany, and they had been particularly requested by the chief of the Secret Service Bureau at Washington to take the matter up.

So far it had been only a matter of correspondence.

Old King Brady knew some things about the business which young Ed Butler did not know, and he was destined to learn still other things from a letter which the boy now delivered.

"When father found he couldn't come he wrote this, Mr. Brady," he said. "My orders were to deliver it to you before we made any talk."

"Ah!" said the old detective. "We will read the letter."

He did so.

It was quite lengthy.

Harry noticed that the old detective read certain parts of it over twice.

Folding it up and putting it in his pocket, at last the old detective turned to Ed.

"Are you much attached to Miss Ethel, my boy?" he asked.

"Why, sure—she's my sister," he replied quickly.

"I want the truth," said Old King Brady. "Certain points in your father's letter require me to ask the question. Be frank and honest now. You were constantly quarreling, were you not?"

"Sometimes we quarreled—yes. Ethel was rather hard on me."

"In other words, if she were not your sister you would not be in the least attached to her?"

Ed nodded, looking surprised.

"Well, I will say then for your benefit that the girl is no relation whatever to you. Your mother, as you are aware, is your father's second wife. You have always supposed Ethel to be your half sister, but she isn't even that. She is the daughter of Mr. Rawson, your mother's first husband by a previous marriage."

"Gee! I'm glad!" blurted the boy. "Now I can say what I really think. She's just horrid! I shouldn't shed a tear if we never found her, and that's a fact."

"So there is one load off your mind," observed the old detective.

"Yes, but why didn't my father tell me?" demanded Ed.

"He had sworn to your mother never to tell you. He instructs me to tell you, so that, in a way, he may not break his word."

"Poor pop," sighed Ed. "He certainly has a hard time of it. But what about Ethel? Is she here in Chinatown, as you supposed?"

"I believe such to be the case. My partner, Miss Montgomery, who has been working for three days on the matter, is to report to us to-night. Disguised as a Chinese woman, she has been in a certain place where she expected to get information, and I have no doubt has done so by this time. We shall soon see her, and then you will know."

"Am I to go along?"

"Yes, by your father's particular request. He says this is the first time you have been to New York. He wants you to learn something of the city and its peculiar ways."

"All right. I have seen enough of it already to make me think that I never want to see it again."

"You decide hastily. If you have come directly from the Grand Central station, as I suppose——"

"That's right."

"Then you have seen very little of it, and that little under unfavorable circumstances. Wait for a daylight view of New York before you decide."

"Where do we go?"

"To a Chinese house around the corner on Mott street."

"I don't see how your partner can work in with the Chinks. Of course, she can't speak Chinese?"

"As it happens she can, and that is just where her advantage comes in. But come, let us go."

They passed out into Pell street.

The rain had now almost ceased, and the wind had died away entirely, but the gutters were running rivers.

"A tremendous amount of water must have fallen," Harry observed.

"Indeed yes," replied Old King Brady. "It has been a terrible storm."

He and Harry walked ahead. Ed walked behind, as there was not room enough on the narrow sidewalk for them to walk three abreast.

"There is more to this case than appears on the surface," Old King Brady whispered to his partner.

"It seems that this wretched girl has robbed Mr. Butler of three thousand dollars in cash, and also of a bunch of valuable papers. He does not want to get her back. His engaging us with that idea is merely a bluff for the benefit of the wife. He does want the papers, however, and if she will give them up he is willing that she shall keep the cash. I am sorry the man did not come himself. There seems to be some mystery about the papers which I fail to understand."

"He makes no explanation of their contents?"

"Nothing further than to say that their loss will probably involve him in a large loss of money. I don't just see what he can mean, for, as I understand it, Mr. Butler is merely working on a salary, and not a very heavy one at that."

"I should like to see the letter. Perhaps I can make something more out of it."

"Possibly, possibly, still I doubt it. I will show it to you first chance I get, and——Good heavens! What was that?"

They had almost reached the point where Mott street joins with Pell.

Suddenly a crash had sounded behind them, and with it came a cry in a boyish voice:

"Help! Mr. Brady! Oh, help!"

Knowing, of course, that it could be no one else than the boy, Ed Butler, the Bradys instantly turned.

The boy had vanished.

Chinamen were running across the street, others were hurrying forward on the same side of the way.

There in the sidewalk was a large, gaping hole.

Two of the flagstones, undermined by the storm, probably, had sunk down just as the Bradys stepped off them.

Ed, less fortunate, had been caught in the break.

"Bless my soul! This is a great piece of business," cried Old King Brady.

Harry peered down into the hole.

It seemed to be pretty deep and it was also very dark.

Young King Brady could see nothing of the boy.

"Hello down there, Ed! Are you hurt?" he called.

"No; I'm all right. I went down with the stone. I'm not hurt a bit," came the answer, "but for heaven's sake get me out of here!"

It was easier said than done. The chattering bunch of Chinks crowding around offered no help.

"I don't see how in thunder we are going to get the boy up without a ladder," muttered Old King Brady.

"And where will we find one?" echoed Harry.

"That's the point. But here comes a policeman. Perhaps he can suggest——"

Thus far in his speech Old King Brady got when there came another call for help.

He could not exactly make out the words, but it was certainly, also, a cry of fear.

"Let go! Don't you touch me!" they heard now.

The cry came from the hole.

Then all was still below, although above the Chinamen chattered louder than ever.

"By Jove! the Chinks are going for the boy," cried Harry. "He has fallen into one of the secret dens of Pell street, sure!"

It looked like it.

The policeman came.

The Bradys turned electric flash lights into the hole.

It seemed to be a brick vault of considerable size.

But there was no one in it so far as they could discover.

Harry's repeated shouts to Ed brought no response.

"I must go down there and look for the boy!" cried Harry.

"Hold on," said the policeman, who was a person they knew; "if the Chinks have got him, they may get you, too. You know what Chinatown is."

"I ought to by this time!" cried Harry. "Lower me down, governor."

"The officer is right," said Old King Brady. "We better be sure than sorry. If we only had a rope."

"Look here, some of youse guys, get a rope!" cried the policeman, charging in among the crowd.

There were enough that understood him.

Some of them started to act.

A moment later a man came out of a Chinese grocery near by with a rope.

It was tied under Harry's arms and he was lowered into the hole.

The floor of the vault had water an inch deep upon it; the brick sides were dripping with a slimy ooze.

But there was no sign of