All the while Bart was watching the girl closely, and he saw that she really intended to get off at Carson.

The boys slipped out of the car, and were on the platform as soon as the pair they were following reached it. It happened that the station platform was crowded, and they were swallowed by the throng, so they found it easy to keep out of sight of the man and girl.

The man seemed to watch to see if the boys left the car, while the girl tried to draw him away. After some moments he submitted, and they entered a closed carriage.

"Here!" exclaimed Frank, catching hold of a sleepy driver and giving him a whirl; "see that carriage?"

"Yep."

"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 x.x.xVIII.

"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 gla.s.s, 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 a.s.sertion by what went before it, and he immediately opened his pocketbook and produced the other bill which he had received of Isa Isban.

"Please look at this, and see if it is also counterfeit," he asked, with remarkable coolness.

In a moment the cashier said:

"It is a mate for the first one. Both are 'queer.' My boy, this is bad stuff to be carrying around. It is liable to bring you into no end of trouble."

As he said this he was regarding Frank's face with a searching stare, as if seeking to discover if the lad were honest or crooked.

Frank knew he was under suspicion, and he bore himself as quietly as possible.

"This is the first intimation I have received that the bills are bad,"

declared the lad. "I received them as I have explained, and I have tried in several places, this morning, to get one of them broken, but did not succeed. I finally came here."

The cashier's brows lowered. He partially closed his eyes, and regarded the boy steadily. Then he began once more to ask questions.

Frank knew he was in an unfortunate situation, and he decided the best thing he could do was to answer every question truthfully, which he did.

It happened there was not much business going on in the bank. The paying teller and the receiving teller listened to the questions and answers.

The receiving teller was a young man, and his face wore a sneering look of incredulity. He regarded Frank with open doubt, and, once or twice, muttered, "Ridiculous!" "Nonsense!" "A clever lie!" or something of the sort.

The face of the paying teller was calm and unexpressive. It seemed that he had not determined in his own mind if the boy were telling the truth.

He was listening to hear everything before he decided.

Frank explained how he came to be in Carson City, having given his name, age, his guardian's name, told where his home was, and answered more than a score of other questions.

The sneers of the receiving teller angered the boy; but he held his feelings in check, and did not seem to hear the man when he proposed that Merriwell be handed over to the special policeman in front of the bank.

"Mr. Merriwell," said the cashier, "I shall have to take possession of these bills."