"Not this morning," she said politely.

She reached in a desk drawer. She brought out paper. She put it in the typewriter and began to type.

Coburn felt very queer. Then he saw something else. There was a fly in the office--a large, green-bodied fly of metallic l.u.s.tre. The inhabitants of Salonika said with morbid pride that it was a specialty of the town, with the most painful of all known fly stings. And Helena abhorred flies.

It landed on the bare skin of her neck. She did not notice. It stayed there. Ordinarily she would have jumped up, exclaiming angrily in Greek, and then she would have pursued the fly vengefully with a folded newspaper until she killed it. But now she ignored it.

Hallen came in, stamping. Coburn closed the door behind him. He felt queer at the pit of his stomach. For Helena to let a fly stay on her neck suggested that her skin was ... somehow not like its usual self.

"What happened to those Bulgarians?" demanded Hallen.

Coburn told him precisely what he'd seen when he arrived in Naousa after an eight-mile hike through mountains. Then he went back and told Hallen precisely what he'd seen up on the cliffside.

"His cameras were some sort of weapon. He played it on the marching column, it took effect and they went to sleep," he finished. "I took them away from him and brought them down, but--"

He told about the contents of the camera cases being turned to a gritty, sooty powder. Then he added: "Dillon set them to destroy themselves. You understand. He's not a man. He's a creature from some planet other than Earth, pa.s.sing for a human being. He's an Invader from s.p.a.ce."

Hallen's expression was uneasy and compa.s.sionate but utterly unbelieving. Helena shivered and turned away her face. Coburn's lips went taut. He reached down to his desk. He made a sudden, abrupt gesture. Hallen caught his breath and started up.

Coburn said curtly: "Another one of them. Helena, is that foam-suit comfortable?"

The girl jerked her face around. She looked frightened.

"Helena," said Coburn, "the real Helena, that is, would not sit down on a dusty chair. No woman would. But you did. She is a very truthful girl.

You lied to me. And I just stuck pins in your shoulder and you didn't notice. They're sticking in your foam suit now. You and the creature that pa.s.sed for Dillon up-country are both aliens. Invaders. Do you want to try to convince me otherwise?"

The girl said evenly: "Mr. Coburn, I do not think you are well--"

Then Coburn said thickly: "I'm crazy enough to put a bullet through you if your gang of devils has harmed the real Helena. What's happened to her?"

Hallen moved irresolutely to interfere. But the girl's expression changed. She smiled. "The real Helena, Mr. Coburn," said an entirely new voice, "has gone to the suburbs to visit her fiance's family. She is quite safe."

There was dead silence. The figure--it even moved like Helena--got composedly to its feet. It got its coat. It put the coat on. Hallen stared with his mouth open. The pins hadn't convinced him, but the utterly different voice coming from this girl's mouth had. Yet, waves of conflicting disbelief and conviction, horror and a racking doubt, chased themselves over his features.

"She admits she's not Helena!" said Coburn with loathing. "It's not human! Should I shoot it?"

The girl smiled at him again. Her eyes were very bright. "You will not, Mr. Coburn. And you will not even try to keep me prisoner to prove your story. If I screamed that you attack me--" the smile widened--"Helena's good Greek friends would come to my a.s.sistance."

She walked confidently to the door and opened it. Then she said warmly: "You are very intelligent, Mr. Coburn. We approve of you very much. But n.o.body will believe you."

The office door closed.

Coburn turned stiffly to the man he'd called to hear him. "Should I have shot her, Hallen?"

Hallen sat down as if his knees had given way beneath him. After a long time he got out a handkerchief and painfully mopped his face. At the same time he shivered.

"N-no...." Then he swallowed. "My G.o.d, Coburn! It's true!"

"Yes," said Coburn bitterly, "or you're as crazy as I am."

Hallen's eyes looked haunted. "I--I ..." He swallowed again. "There's no question about the Bulgarian business. That did happen! And you were there. And--there've been other things.... Rumors.... Reports that n.o.body believed.... I might be able to get somebody to listen...." He shivered again. "If it's true, it's the most terrible thing that ever happened. Invaders from s.p.a.ce.... Where do you think they came from, Coburn?"

"The creature that looked like Dillon could climb incredibly fast. I saw it run and leap. Nothing on Earth could run or leap like that." Coburn shrugged. "Maybe a planet of another sun, with a monstrous gravity."

"Try to get somebody to believe that, eh?" Hallen got painfully to his feet. "I'll see what I can do. I ... don't know that I can do anything but get myself locked up for observation. But I'll call you in an hour."

He went unsteadily out of the door. Coburn instantly called the Breen Foundation on the telephone. He'd left Janice there less than an hour before. She came to the phone and gasped when she heard his voice.

Raging, he told her of Helena, then cautioned her to be especially careful--to be suspicious of everybody.

"Don't take anybody's word!" snapped Coburn. "Doubt everybody! Doubt me!

Until you're absolutely certain. Those creatures are everywhere.... They may pretend to be anybody!"

After Coburn hung up on Janice, he sat back and tried to think logically. There had to be some way by which an extra-terrestrial Invader could be told instantly from a human being. Unmask and prove even one such creature, and the whole story would be proved. But how detect them? Their skin was perfectly deceptive. Scratched, of course, they could be caught. But one couldn't go around scratching people.

There was nothing of the alien creature's own actual form that showed.

Then Coburn remembered the Dillon foam suit. The head had been hollow.

Flaccid. Holes instead of eyes. The creature's own eyes showed through.

But he'd have to make certain. He'd have to look at a foam-suited creature. He could have examined Helena's eyes, but she was gone now.

However, there was an alternative. There was a Dillon in Salonika, as there was a Helena. If the Dillon in Salonika was the real Dillon--if there were a real Dillon--he could look at his eyes. He could tell if he were the false Dillon or the real one.

At this hour of the afternoon a Britisher would consider tea a necessity. There was only one place in Salonika where they served tea that an Englishman would consider drinkable. Coburn got into a cab and gave the driver the address, and made sure of the revolver in his pocket. He was frightened. He was either going to meet with a monster from outer s.p.a.ce, or be on the way to making so colossal a fool of himself that a mental asylum would yawn for him.

He went into the one coffee-shop in Salonika which served drinkable tea.

It was dark and dingy inside, though the tablecloths were spotless. He went in, and there was Dillon.

Coburn's flesh crawled. If the figure sitting there with the _London Times_ and a cup of tea before him were actually a monster from another planet ...

But Dillon read comfortably, and sipped his tea. Coburn approached, and the Englishman looked up inquiringly.

"I was ... up in the mountains," said Coburn feverishly, "when those Bulgarians came over. I can give you the story."

Dillon said frostily: "I'm not interested. The government's officially denied that any such incident took place. It's merely a silly rumor."

It was reasonable that it should be denied. But it had happened, nonetheless. Coburn stared, despite a consciousness that he was not conspicuously rational in the way his eyes searched Dillon's face hungrily. The eyes _were_ different! The eyes of the Dillon up in the mountains had been larger, and the brown part--But he had to be sure.

Suddenly, Coburn found himself grinning. There was a simple, a perfect, an absolute test for humanity!

Dillon said suspiciously: "What the devil are you staring at me for?"

Coburn continued to grin uncontrollably, even as he said in a tone of apology: "I hate to do this, but I have to be sure...."

He swung. He connected with Dillon's nose. Blood started.

Coburn zestfully let himself be thrown out, while Dillon roared and tried to get at him through the flying wedge of waiters. He felt an enormous relaxation on the way back to his office in another cab. He was a trifle battered, but it was worth it.