When they reached the street, Harry cried:

"That Mason was a clever schemer. But we've foiled his plan to palm off a stranger's body for that of the missing broker. We must let Lizzie Dalton know how she was duped. There's every possibility yet that her father is still alive. With this doubt pending, the will need not be probated yet."

"Steps have already been begun to test the signature," said Old King Brady. "By this afternoon we shall know positively whether that signature to the will is a forgery or not."

"And if it is?"

"We'll have to run down Mason and make him pay the penalty of his crime," replied the veteran detective, decisively.

They then went up to the Dalton house.

Lizzie was at home and heard what Kelly confessed.

Her joy and astonishment knew no bounds, and she cried:

"Then there is some probability that my poor father yet lives!"

"Yes, indeed," replied Harry, "and it is our belief that he is still concealed down South in the big swamp on his estate. We are going back there to investigate the matter."

"And I sincerely hope you will be successful in finding him," fervently replied the girl. "In fact, I am so anxious about the matter that I shall go down to Swamp Angel myself as soon as I can get my affairs so regulated here that I can go away."

"Then we shall meet there."

"I hope so. And if your work is going to keep you in the vicinity of our place, I want you to make your headquarters there."

They thanked her for the invitation and after some further talk they left the house and headed for the writing-expert's office.

The professor was located on Broadway near Chambers street.

He was in when they called.

They had furnished him with several check-vouchers, and other specimens of Mr. Dalton's handwriting procured at his office.

He greeted them warmly and asked, with a smile:

"I suppose you are curious to learn the result of my labors?"

"We are," a.s.sented Old King Brady, taking a chew of tobacco.

"I've finished my investigations."

"And what is the result?"

"That signature is a rank forgery."

"A poor one?"

"Very."

"Let us see."

"I'll magnify the writing."

He had a projecting machine, and, lighting it, he placed the signature on the will and several more signatures of Mr. Dalton in the machine.

The names were reflected on a sheet, in enormous proportions.

Three were exactly alike, but the fourth was entirely unlike them.

Magnified, the finest lines of the writing were now as coa.r.s.e as a broom handle, so that every little mark was plainly visible.

"Explanations are useless here," said the expert, smilingly. "You can easily see for yourself all I could tell you. The three signatures which are alike are taken from a check, a letter and a bill. You will notice there isn't the slightest deviation in any of the lines from the fixed method Mr. Dalton had of signing his name. The odd-looking signature is the one affixed to the will. Here you will see that the loops, straight lines, curves and angles are all entirely unlike the original; the width of the lines and shading are different, and the angle at which the letters are set is not the same as that in the others."

The Bradys saw all this and more, too.

In fact, they had every evidence before them that the will was a base forgery and they were well satisfied.

With this fact established, they went to the Central office.

Here they encountered their chief.

Old King Brady detailed to him all that transpired, and he listened very attentively until the detective finished.

Then he pondered a moment, and said:

"The whole thing is a big plot on Mason's part to get his uncle's money and daughter at one swoop."

"We've clearly established Mason's guilt, sir."

"Very true. He's a bad egg. Capture him and you may find out what he has done with Oliver Dalton."

"I've become convinced of another fact since finding out what a villain that fellow is," said Old King Brady.

"To what do you allude?"

"Well, you recollect that when we began this case it was for the purpose of finding out who was stealing money from the broker's mail,"

said the detective.

"I'm aware of that."

"In view of all that happened, it begins to look as if Mason was the guilty party the Federal Government is after."

"It wouldn't surprise me a bit if you brought home that crime to his door," said the chief. "If, as you say, he had such extensive control of the business, he must have handled all the mail. It would then have been an easy matter for him to purloin the contents of many of the envelopes without being detected."

"The misfortune now is that he's gone so we cannot set a trap to catch him in the act," said Old King Brady. "If anything now is found out about the matter, it will only be learned from Mason himself making a clean breast of the crooked work."

"Convict him of his other misdeeds," said the chief, lighting a cigar, "and you'll have evidence enough to send the villain to jail for a long time. If Mr. Dalton is dead, you can lay the crime at his door, for he was the only person in the world who hoped to be benefited by the demise of his benefactor."