Roy alone had grasped the possibility that Captain Hardy might not be able to remain with them. Now every eye was fixed anxiously on Captain Hardy's face.
"No," he said, "I do not have to return to Washington. It is of the utmost importance to catch these spies and the government could well afford to give up one ordinary doctor in order to get four skilled spy hunters." He paused and smiled, then added: "So I have been detailed to special duty in New York."
The boys could hardly repress a shout of joy.
"And my instructions," continued Captain Hardy, "were to get into touch with the police and the secret service immediately. As I have told you, we must get acquainted with both. But before we do, I suggest that we take a look at the town where we are to work in the days to come. Let's be moving."
They rose and passed through the station. Its great vaulted ceiling, half as high as a church steeple, its huge flights of steps, its enormous corridors, its wonderful stonework, dwarfing into insignificance anything they had ever seen before, fairly awed the boys from Central City. It was Roy's keen eye that caught sight of the great maps of the world high up on the walls. The crowds of people coming and going hardly seemed like crowds, so vast was the structure. With reluctant feet the four boys pushed on. But when they had mounted the steps to the arcade and caught sight of the illuminated transparencies showing scenes along the railway's path, they came to a dead stop. For Willie Brown, with his almost uncanny eye for landscapes, at once declared that a certain picture represented a mountain scene not twenty-five miles from Central City; and when the others appealed to Captain Hardy, the latter confirmed Willie's statement.
When the four lads reached the sidewalk they were almost distracted. Thousands of people were hurrying along, passing in endless throngs up and down the street. Never had the boys from Central City seen people in such a rush.
"What's the hurry?" demanded Roy. "Why does everybody walk so fast? What's up?"
"Nothing," replied Captain Hardy, with a smile. "That's just the New York gait. Everybody walks fast here, and does everything else fast; and if you boys want to make a reputation in New York you'll have to hustle some. But I don't want you to make that kind of a reputation," he continued, hastily yanking Willie Brown from in front of a passing motor-car. "You will have to keep your eyes open here."