A couple of hours before his appearance in the room that morning, the Secret Service agent had left the boys in the lobby below to arrange for the necessary papers and funds for the mission. Before going out, however, he had been informed of the boys' suspicions, and had made light of the idea that the aeroplane was in danger from secret enemies, pointing to the fact that no one was supposed to know anything about the proposed journey save the boys and himself as conclusive evidence that the suspicion of constant surveillance was not well founded.
Now, on his return, his cautious movements indicated that he, too, was alarmed and on his guard. While Ned was wondering what it was that had so changed Gates' point of view, there came a quick, imperative knock on the door of the room, which was occupied by Ned and Jimmie as a sleeping apartment.
Instantly, almost before the sound of the knock died away, Gates opened the door and stepped forward. The man who stood in the corridor, facing the doorway, was tall, slender, dark of complexion, like a Spaniard or a Mexican. His black hair was long, straight, thin; his black eyes were bright, treacherous, too close together, with a little vertical wrinkle between the brows. He was dressed in a neat brown business suit of expensive material.
When the door was opened he stepped forward and glanced into the interior of the room, apparently with the purpose of entering. But when Gates moved aside to give him passageway he drew back, the set smile on his face vanishing as he bowed low and swung his slender hands out in elaborate gesture.
"Pardon!" he said. "I have made a mistake in the room."
He was about to move away when Gates gritted out a question.
"For whom were you looking?" he asked. "We may be able to direct you to your friend," he added, more courteously, his alert eyes taking in every detail of the man's face, figure and dress.
"It is nothing!" was the quick reply. "I will make inquiries at the office—which, undoubtedly, I should have done before."
In a moment he was gone, moving gracefully toward the elevator. Gates watched his elegant, well-dressed figure with a smile of quiet satisfaction. When the visitor gained the elevator, he turned and bowed at the still open doorway, and the Secret Service man recognized the grin on his face as expressive of triumph rather than apology.
"What did he want?" asked Jimmie, as Gates, closed the door.