“Why, that’s nonsense!” he exclaimed hotly. “We’ll be back as soon as we can, and if they make any more inquiries you can tell them so. And when we do come back, they won’t have any further excuse for holding us, for we’ll have the real mail robbers with us.”
“I hope you are right, Frank. If your father comes back, I’ll tell him you called.”
“All right, Mother. And don’t worry about us. We’ll be back home as soon as we can get away.”
Frank hung up the receiver and paid the cost of the call. When he turned toward Joe, however, he found his brother standing in the door, gazing up at the sky.
“They’re away already!” exclaimed Joe excitedly. “Look!”
Frank ran to the door. Joe was pointing up at the clouds. High above them soared an airplane, drumming its way toward the south.
“I saw it rise,” said Joe. “It took off from one of those farms back of the village. It’s Ducroy’s crowd, sure as guns.”
“On their way to the flying field already. Well, we’d better be moving.”
They hurried down the street toward the hotel, where they had left the roadster. On the way, Frank told Joe the result of his telephone call. Joe too was disappointed that they had not been able to get in touch with Fenton Hardy.
“It means we have to play a lone hand, that’s all. What do you think we should do next, Frank?”
“I think we ought to tell the authorities.”
“We’ll warn them to watch the airplane hangars on the twenty-eighth and twenty-ninth,” said Joe. “But we mustn’t lose sight of Ducroy and his cronies.”
They looked back. The airplane was merely a blur in the distance. The boys realized that they had no time to lose. They scrambled into the roadster. Frank threw in the clutch and the car shot forward. Within a few minutes they were speeding down a road toward the south in the direction of the Riverside Field.
XVII
Dangerous Business
When the Hardy boys arrived at Riverside Field they looked in vain for Giles Ducroy and his friends. But the trio were not in sight, and there was but one airplane on the flying field. It was a small two-seater.
“It can’t be their plane,” said Frank. “Ollie Jacobs said it would hold four or five men.”
“Perhaps they haven’t arrived yet,” Joe suggested.
“They had only thirty miles to go. They should have been here long ago.”
“We can go up to one of the hangars and ask what planes have come in.”
Frank was dubious. “If Ducroy or any of the others are hanging around, we’ll be spotted. Our game is to keep out of sight.”
They sauntered over to the solitary little airplane in the middle of the flying field. A mechanic in grimy overalls was busy tinkering at the understructure of the machine.
“Is this the only plane here?” asked Frank politely.
The mechanic looked up. “It’s the only one out on the field,” he answered. “If you can see any more, let me know.” He grinned, and then waved toward one of the hangars. “An old crate just flew in a few minutes ago.”
“Where from?”
“How should I know? Airplanes, unless they’re on the mail run, aren’t like trains. Looked to me like a privately owned machine.”
The Hardy boys glanced significantly at one another. They had no doubt that this was Ducroy’s plane.
“Is the pilot in there now?”
The mechanic nodded. “Him and two other guys.”
Frank and Joe thanked their informant and made a wide detour across the flying field so as to approach the hangar at the far side. They had no desire to meet Giles Ducroy and his friends just now. They came around to the rear of the hangar without being observed and while they were looking about for a means of entrance other than by the front, Joe discovered a small door at the side.
He tried the door. It was unlocked. Joe edged it open and peeped in.
There was the plane, at rest in the hangar, and standing beside it were Giles Ducroy, Newt Pipps, and Ollie Jacobs. They were talking in low tones. Even as the boys watched they saw Ollie Jacobs move away from the others.
“It won’t take long,” he said. “I’ll do some telephoning and find out all I can.”
“Make sure of the date!” advised Ducroy.
Ollie Jacobs left the hangar. For a moment the Hardy boys were panic-stricken at the thought that he might look back and see them pressed against the side of the building, but Jacobs strode away without once glancing behind.
“I wish we could learn something definite,” whispered Joe. “This thing of following them around is beginning to get on my nerves. They are bound to catch sight of us, sooner or later.”
“We certainly can’t follow them around like this,” agreed Frank. “If they don’t see us, we’re liable to lose them anyway. If we can only find out what game they’re up to!”
They peeped through the opening in the door again. But Ducroy and Newt Pipps had withdrawn a little way to one side and were talking in undertones, their words inaudible.
In about ten minutes, Ollie Jacobs returned. He hastened into the hangar, and Ducroy looked at him expectantly.
“Well,” the boys heard Ducroy saying, “did you learn anything?”
“I sure did,” returned Ollie Jacobs. “It’s all settled. And we don’t have to wait as long as we thought we might.”
“That’s good,” declared Ducroy, rubbing his hands together with satisfaction. “What did he say?”
“The shipment will come on the night of the twenty-eighth.”
“As soon as that!” exclaimed Newt Pipps.
“We’ll be ready for it,” snapped Ducroy. “We’ll force him down not far from here.”
“It will be at night, eh?” said Pipps.
“Of course. All the better, too. I’d think twice before I’d try this trick in daylight.”
“I guess you’re right,” admitted Newt feebly. “Although I don’t like the idea of it at any time. You’re sure we’ll have only one man to handle?”
“Only one man. And there are three of us. We’re not
