147 "He said you were to report to him as soon as you came in."

The boys hastened off. They could not imagine what the director wanted with them.

"Hope it doesn't mean trouble," said Frank. "Maybe Boots has been talking to him."

But it did not mean trouble. The director was a kindly, twinkling-eyed man who shook hands with them in the friendliest manner. He said a gentleman was there to see them. It was against the rules for the workers to have callers, but he was making an exception this time.

'' I know your father well,'' he smiled. '' Fine man. And I understand you boys are following in his footsteps, and already are working on some case out here. After you see your caller, look me up again."

Tim 0 'Brien, the person waiting to see them, was the new night watchman from the road construction job. Honesty was written on hia broad features.

"Young Mr. Ames asked me to stop in to see you on my way home for some sleep," he told the boys. "But actually I won't sleep, for that's what I did all night, when I was supposed to be guardin' the stuff out there," he added ruefully.

"d.i.c.k says he thinks you were drugged," spoke up Frank.

"I guess so. That stuff I smelled was the foulest thing anybody ever had near him."

148 '' What was it like ?'' asked Joe.

"Nothing alive," the watchman answered. "More like a dead animal that hadn't been buried.''

"But that shouldn't have put you to sleep for so many hours," said Frank. "I believe the thief who did it used the strange stuff first, then followed it up with ether or something else that wasn't noticeable to you, but put you to sleep."

'' Clever,'' grunted 0 'Brien. ' ' ' But if I ever lay my hands on the guy-" He did not p.r.o.nounce But if I ever lay my hands on the guy-" He did not p.r.o.nounce his threat. Instead, he stood up and said good-by to the boys. "If you catch him, let me know."

After he had gone, the Hardys returned to the S. E. F. Director. He was reading a label on a small bottle he held in his hand. It had seeds inside.

"Here's something interesting," he remarked. "I'll admit these seeds don't look look interesting, but they're fifty years old, and I'm about to plant some of them."

"They won't grow, will they?" asked Joe.

"I expect them to. And ten years from now we'll plant some more of them."

The boys thought he was joking. They had never thought a seed could grow after fifty years. But the director a.s.sured them that it was quite possible, and that it was one of the most important experiments being carried on at the farm.

149 "It only goes to show that plant life is practically indestructible,'' remarked the man. '' A grain of wheat taken from an Egyptian tomb actually grew after being buried for five thousand years!"

The boys were impressed. Each day they were gaming a better understanding of the important work of experimental farming.

"We were told something about the African lily pollen the other morning," said Joe.

'' Oh, yes-that stuff. Smells!'' laughed the director.

"Would it be possible for us to get a sample?" asked Frank, who had been mulling over an idea in his mind.

"Yes, indeed," beamed the man, "as long as you don't waste it playing tricks on your friends." He took a pad of paper from his pocket and scribbled a few words on it. '' Here's an order on the laboratory sample room. The clerk will give you some of the evil-smelling stuff."

Frank and Joe found their way to the laboratory. The clerk in the sample room glanced at the order slip.

"African lily pollen, eh? Sure, I can fix you up with some of that. There's a whole bottle of it right here.''

He turned away, ran his fingers along one of the crowded shelves. Then his hand paused at an empty s.p.a.ce.

150 "Why-why, it's gone!" he exclaimed. "I can't understand this."

"Maybe somebody took it to use for an experiment," Frank suggested.

But the clerk said that would have been impossible without a written order. And no order had been filed for the African lily sample. The man was upset and frantically searched all the shelves, on the chance that the bottle might have been misplaced. But it was not there.

"I can't understand it," the clerk said.

But the Hardy boys could. As they returned to the director to tell him, Frank remarked : "I'm sure someone stole that sample to use on the watchman."

"And that someone," declared Joe with conviction, "was Boots 1"

CHAPTER XVIII.

A MYSTERIOUS APPOINTMENT.

the Hardy boys hurried back to tell the director the bottle of pollen was missing. The man was not unduly disturbed.

"Probably the clerk put it on the wrong shelf. Or maybe someone needed the sample in a hurry and the clerk was off duty at the time, so the bottle went out without being entered in the records. I have some of the stuff in my private office, anyhow. Come along and I '11 let you have some of it."

On the way Frank ventured an inquiry about Boots.

"An interesting character," he remarked innocently. "We were working with him the first day we came here."

"Oh yes-Boots. Very interesting fellow," said the director. '' He was hired by us, because he knows a good deal about rice culture, and the information was valuable to us in our underwater farming."

"Where did he learn about rice?" asked Joe.

"He was shipwrecked on an island somewhere in the Orient, I believe. He's had quite a history. Bather gruff in his manner, but he's a good workman and honest."

151.

152 The Hardy boys were a little surprised by this high recommendation of Boots. As they waited for the director to locate the bottle, a figure pa.s.sed beneath one of the open office windows. The fellow had been lurking there and had heard the entire conversation.

"Those two boys are gettin' awful smart," he muttered as he went off.

"Here you are, my boy. Here's the horrible African lily pollen," smiled the director, coming back with a tiny vial. '' Don't let any of it get on your clothes, or you'll both be as unpopular as a pair of polecats!''

Smiling, the boys thanked him and promised to take good care of the rare stuff. They were glad, nevertheless, that the director did not ask them why they wanted it.

"Just as soon as we finish work this afternoon," resolved Frank, "we'll look up O'Brien and find out if this is what he smelled last night. And if it is------"

"If it is," Joe declared, "I think we'll have a first-rate clue to that robbery. With Mr. Boots right in the middle of it, I don't care what the director says about him."

When their day's work was over, the boys went directly to the garage where they had left their car to be repaired. They arrived, fully expecting that they would drive it away at once.

The young mechanic in charge of the place at the moment astounded them by saying: 153 '' Your car ? It went out an hour ago.''

"Went out?" exclaimed Frank. "Why was that? We gave no one permission to use it."

"But you sent your sister for it, didn't you? She came here and picked up the car. Said you told her to call for it.''

The Hardy boys were astounded.

"Sister!" cried Joe. "That's the first I've heard about her. We haven't a sister." cried Joe. "That's the first I've heard about her. We haven't a sister."

Now the mechanic was worried. '' Gee whiz!'' he exclaimed. '' Do you mean to tell me I turned that car over to the wrong person? The girl said she was your sister. She was so cool about it, I didn't dream there was anything wrong. Oh, my boss will certainly fire me for this!"

The Hardy boys pressed him for a description of the "sister" who had claimed their automobile. The fellow said he had not noticed her particularly.

'' She had on a large hat with a veil, and had a rather deep voice, for a girl," he remembered. "Walked with a long stride. She paid for the repairs, and seemed to know all about the car, so naturally I thought it was all right.'' He indicated tire tracks in the dirt road. ''

There are the tracks of the car."

The Hardy boys decided to follow them, so they hurried back to the Experimental Farm to borrow two horses. They found it easy to distinguish the tire marks, for there had been very little traffic on the dirt road since the stolen 154 automobile had been driven off. But when the trail reached a paved highway, it vanished utterly.

"I have an idea about that 'sister' of ours," muttered Frank darkly. "From what the mechanic said, I I think 'she' was not a girl at all." think 'she' was not a girl at all."

"A boy in girl's clothes!"

Frank nodded. " It's all part of the mystery. We 'd better report the stolen car to the police."

They rode quickly to Mrs. Trumper's. The widow groaned with dismay when they told her of the loss of their automobile.

"I never did know of such a run of bad luck. First your house burns, and now your car gets stolen!"

"The house didn't burn down, anyway, and maybe we'll get the car back," said Frank cheerfully.

He telephoned the Bayport police office and reported the loss of the car. The desk sergeant a.s.sured him the description and number of the automobile would be flashed to the state police and to other communities at once. There was nothing more the boys could do but wait and hope for the best.

"Here's a note that came for you about a quarter of an hour ago," Mrs. Trumper said.

"Hearing about your ear made me forget about it. I hope it isn't more bad news."

She handed Joe a folded slip of paper. He opened it and read aloud: 155 "IP YOU WELL. COMB TO THE UNDERWATER SECTION AT ELEVEN O'CLOCK.

TONIGHT, I'LL TELL YOU WHO TOOK THE SAMPLE BOTTLE OF THE AFRICAN LILY.

POLLEN. AND I'LL HELP YOU CATCH THE THIEF WHO STOLE IT.

SAMPLE ROOM CLERK, S. E. F.".

Joe turned the strange missive over. Nothing else was written on it. There was no name, no address, no further signature.

"What do you think of it?" he asked Frank doubtfully.

"I don't like it." His brother studied the note. "I think it's a hoax."

"On the other hand, if it isn't a hoax, maybe we'd miss something important if we don't go."

Frank thought for a moment. '' Our best plan is to find out more about that sample room clerk. He probably rooms in the village, like most of the Farm employees. Let's check up on him."

They said good-by to Mrs. Trumper who warned them to be careful. On horseback the boys clattered out of the lane and down the country road to the village. A boy in the ice cream parlor was able to tell them about the sample room clerk at the State Experimental Farm.

"Sure," said the lad, "that's George Gilman. But you won't find him for a while. He took his girl to Bayport to a movie."

156 "You don't happen to know when he might get back, do you ?'' asked Frank.

"I heard her tell him she had to be home by ten-thirty," grinned the boy. "And he said that heard her tell him she had to be home by ten-thirty," grinned the boy. "And he said that was all right by him, 'cause he had another date at eleven o 'clock.''

The Hardys heard no more. They looked at each other knowingly, thanked the boy, and left.

"Well, I guess we show up at the S. E. F. at eleven o'clock," said Joe in a whisper. "Say, look!"

There was a cheap restaurant across the street. Through the front window the boys could see the white-topped tables. At one of them two men were seated, leaning forward in earnest conversation.

Joe whistled. "So those two know each other!" he exclaimed shortly.

The Hardy boys had good reason to be surprised. For the men were Boots and Hefty Cronin.

The Hardy boys remained where they were, watching. After a while Boots got up and left the restaurant. Hefty Cronin sat idly at the table for a few minutes, then he too arose and left the place. Boots shambled off down the street. Cronin climbed into a truck parked near by and drove away.

"I'd give a lot to know what those two were talking about," remarked Frank.

"I'd give a lot to know what's going to hap-157 pen when we show up for that date at eleven o'clock!"

They were still inclined to believe it might be a trap. In this case they would enter it with their eyes open. This might even turn out to be an opportunity to come to grips with hidden enemies.

A few minutes before eleven o'clock that night the two Hardys on horseback rode slowly into the grounds of the Experimental Farm. The place seemed deserted. By night the paths lay in eerie shadows. In the underwater section the air was filled with the odor of the swampy tanks where Boots grew his weeds and plants. The atmosphere was sinister and uncanny.

The boys drew their horses to a stop. Already they had planned a course of action. To guard against surprise, they had arranged to face their horses in opposite directions, so that each boy, high in the saddle, could scan a different part of the grounds. Any one approaching by the path, thus would not be able to steal up on them un.o.bserved.

But the Hardy boys had reckoned without the crafty wits behind the note that had lured them to the place. Both of them knew about the high platform above the tanks. They had seen it often in their work around the Farm. It loomed just above the level of their shoulders, a dark oblong shadow in the night.

So absorbed were they in watching the 158 ground that neither of them saw the first slight movement on the platform. Slowly a head was ^aised-a head without face or features-a head grimly hooded, with eyes that peered through ragged slits in the rough cloth.

Then another hooded head appeared. The figures arose, crouching, gazing malignantly at the boys below them. There was a silent signal. Both figures launched themselves suddenly from the platform. They flung their robes over the boys, hurling them from their saddles!