check the lab there.'
Mr. Hardy leaned back in his chair and rubbed the bruise on his temple. In a low voice he said,
'But I didn't make it. I was running toward the hall when there was a roar and a burst of flame.
The explosion lifted me off my feet and threw me against the wall. Though I was stunned, I
managed to get back to the east wing. I reached for the phone, then blacked out.
'I must have been unconscious for some time because when the firemen found me and helped
me out of the building, the fire had been put out.'
'You're all right now?' asked Frank. 'Yes. It was a temporary blackout from shock. What bothers me is that I had the saboteurs' pattern figured out-only they must have become
panicky, and moved up their nefarious scheme two days.'
Joe looked grim. 'I wish we'd been there to help you capture those rats!'
Chet asked Mr. Hardy if he would like a fruit drink. 'I'll make some lemonade,' he offered.
'Sounds good.' Mr. Hardy smiled. As they sipped the lemonade, Frank and Joe questioned their father about his theories.
'I'm still convinced,' said Mr. Hardy, 'that one of those men works in the plant. How else would he have known when the watchman makes his rounds and how to disconnect the electronic
alarms? But I can't figure how the outside accomplice got in-those gates are carefully guarded.'
At this point, Frank told his father about the green truck. 'We suspected at first it might be connected with the counterfeiters. Now we have a hunch the saboteurs may have used it.'
Fenton Hardy seemed greatly encouraged by this possible lead. Joe gave him the license
number, which Mr. Hardy said he would report to Chief Collig at once.
When Mr. Hardy returned from the telephone, he told the boys the chief would check the
license number with the Motor Vehicle Bureau in the morning and by then he also would have
some information about the print on the archer's finger guard.
The next morning after breakfast Frank said he wanted to take another look at the warning
notes.
'Why?' Joe asked curiously as they went to the file.
Frank held up the 'arrow' warning, and the one received by Chet. 'I've been thinking about the printing on these two-seems familiar. I have it!' he burst out.
'Have what?' Joe asked.
'This printing'-Frank pointed to the papers -'is the same as the printing on Ken's envelope addressed to Victor Peters. I'm positive.'
Excitedly the brothers speculated on the possible meaning of this clue. 'I'd sure like to find out,' said Joe, 'who addresses the envelopes Ken delivers, and if they're always sent to Mr.
Peters in the Parker Building. And why-if he doesn't have an office there. And who is Victor
Peters?'
'If the person who addresses the envelopes and the sender of the warnings are the same,'
Frank declared, 'it looks as though he's sending something to a confederate, under pretense of having work done for Elekton. I wonder what that something could be?'
'At any rate,' Joe added, 'this could be a link either to the counterfeiters or to the saboteurs.
Which one?'
The boys decided to go out to the mill again, in hopes of quizzing Ken Blake. Just then their
father came downstairs. Frank and Joe were glad to see that he looked rested and cheerful.
Mr. Hardy phoned Chief Collig. When the detective hung up, he told his sons that the license
number belonged to stolen plates and the fingerprint to a confidence man nicknamed The
Arrow.
'He's called this because for several years he worked at exclusive summer resorts, teaching archery to wealthy vacationers, then fleecing as many of them as he could. After each swindle, The Arrow disappeared. Unfortunately, there's no picture of him on file. All the police have is a general description of him.'
Frank and Joe learned that the swindler had a pleasant speaking voice, was of medium height,
with dark hair and brown eyes.
'Not much to go on,' Joe remarked glumly.
'No, but if he is working for Elekton, he must be pretty shrewd to have passed their screening.'
Mr. Hardy agreed, and phoned Elekton, requesting the personnel department to check if
anybody answering The Arrow's description was employed there.
The brothers then informed their father about the similar lettering on the warnings and Ken's
Manila envelope.
'A valuable clue,' he remarked. 'I wish I could go with you to question Ken.' The detective explained that right now he had to make his report of the explosion to the nearby FBI office.
When he had left, Frank and Joe rode off to the mill on their motorcycles.
At the gatehouse the guard had unexpected news. 'Ken Blake isn't working here any more,'
Mr. Markel said. 'We had to discharge him.'
'Why?' asked Joe in surprise.
The guard replied that most of the necessary jobs had been done around the mill grounds. 'Mr.
Docker-my coworker-and I felt we could handle everything from now on,' he explained.
'I see,' said Frank. 'Can you tell us where Ken is staying?'
Markel said he was not sure, but he thought Ken might have been boarding in an old farmhouse
about a mile up the highway.
When the brothers reached the highway, they stopped. 'Which way do we go? Mr. Markel
didn't tell us,' Joe said in chagrin.
'Instead of going back to find out, let's ask at that gas station across the way,' Frank suggested.
'Someone there may know.'
'An old farmhouse?' the attendant repeated in answer to Frank's query. 'There's one about a mile from here going toward Bayport. That might be the place your friend is staying. What does he look like?'
Frank described Ken carefully. The attendant nodded. 'Yep. I've seen him ride by here on his bike. A couple of times when I was going past the farm I noticed him turn in the dirt road to it.'
'Thanks a lot!'
The Hardys cycled off quickly. Soon they were heading up the narrow, dusty lane, which led to a ramshackle, weather-beaten house. The brothers parked their motorcycles among the high
weeds in front of it and dismounted.
'This place seems deserted!' Joe muttered. Frank agreed and looked around, perplexed. 'Odd that Ken would be boarding in such a rundown house.'
Frank and Joe walked onto the creaky porch and knocked at the sagging door. There was no
answer.
They knocked again and called. Still no response.
'Some peculiar boardinghouse!' Joe said. 'I wouldn't want a room here!'
Frank frowned. 'This must be the wrong place. Look-it's all locked up and there's hardly any furniture.'
'I'll bet nobody lives in this house!' Joe burst out.
'But the attendant said he has seen Ken riding in here,' Frank declared. 'Why?'
'Let's have a look,' Joe urged.
Mystified, Frank and Joe circled the house. Since they were now certain it had been abandoned, they glanced in various windows. When Joe came to the kitchen he grabbed Frank's arm
excitedly.
'Somebody is staying here! Could it be Ken?'
Through the dusty glass the boys could see on a rickety table several open cans of food, a
carton of milk, and a bowl.
'Must be a tramp,' Frank guessed. 'I'm sure Ken wouldn't live here.'
