"Don't lose sight of it for a moment, but do not seem to follow it.
Understand?"

"I reckon."

"Good! If you do the trick well, you get a tenner."

"Got it?"

"See."

Frank showed his roll, on the outside of which were the bright new
fifty-dollar bills.

"Get in."

The boys sprang in lively, the door closed on them, the driver leaped to
his seat, the whip cracked, and away they went.

"This is the first time I ever played the detective," said Bart.

"But it is not the first time for me," declared Frank. "I have found it
necessary, several times, in New York, Chicago, New Orleans and
elsewhere."

"I noticed how ready you were to do the proper thing. You did not give
them the start."

"Not a bit of it."

"You are the same old, self-reliant, hustling, go-ahead Frank Merriwell.
The only changes I can see in you are for the better."

"Thank you."

The driver in advance was a hustling fellow, and he had two good horses.
He sent them right along. Now, it was fortunate that, although, the
driver behind was a sleepyhead, he, also, had some fine horses, and he
did not make any great effort to keep them at a clipping pace.

It is probable that the man with the black mustache regarded the boys
with no little contempt, for he surely made no effort to give them the
slip. It is likely he did not fancy they would follow him so hotly.

At length the carriage in advance stopped before a certain house, and
the driver got down to open the door.

The driver who was carrying the boys continued past, turned the first
corner, stopped short, jumped down, opened the door, and said:

"Got 'em? They're just round the corner back yon."

"And you have earned your X," said Frank, springing out.

CHAPTER XXXVIII.

"QUEER" MONEY.

"This is counterfeit!"

It was in the First National Bank of Carson, between nine and ten
o'clock of the day following Frank's arrival in the city.

Frank had found it difficult to get either of the new fifty-dollar bills
changed, and so he stepped into the bank and asked if he could be
favored there.

The bill had been scrutinized closely, the cashier had examined it
beneath a magnifying glass, after which he questioned the boy concerning
his manner of obtaining the paper, and Frank had told the truth fully
and without hesitation. Then the boy had been called into a private
room, and the cashier had declared the bill counterfeit.

Frank had been prepared for such an assertion by w