He had seen one woman change into a man on the train, and here was another and no less startling metamorphosis.

“Driver,” he cried, “didn’t you take a person on in woman’s clothes at the station and let one off in man’s clothes just now?”

“None of yer business!” came the coarse reply. “I knows enough not ter answer questions when I’m paid ter keep still.”

That was quite enough; the driver might as well have answered, for he had satisfied Merriwell.

Frank was astonished by the remarkable change that the woman had made while within the cab, but now he believed he understood why she had not been detected while on the train. She had been able to make a change of disguises in the toilet room, and had passed herself off as a man. Hodge had looked for a veiled woman, and he had looked for a veiled woman; it was not strange that both of them had failed to notice a person in masculine attire who must have looked like a woman.

Up the hotel steps Frank leaped. He entered the office, he searched and inquired. At last, he found out that a beardless man had entered by the front door, but had simply passed through and left by a side door.

“Given me the slip,” decided Frank. He realized that he had encountered a remarkably clever woman.

And the mystery was deeper than ever.

Frank went to the hotel at which the company was to stop, and found all save Wynne had arrived. Hodge was on the watch for Merry, and eagerly inquired concerning his success in following the woman. Frank explained how he had been tricked.

“Well, it’s plain this unknown female is mighty slippery,” said Bart. “You have not seen the last of her.”