I've got news for you, Gregg." He went abruptly solemn and lowered his voice. "Halsey wants to see us, right away."

I regarded him blankly and my mind swept back. No more than a few short weeks ago Detective-Colonel Halsey of Divisional Headquarters here in Greater New York had sent for us, and we had been precipitated into the Grantline affair. "Halsey!" I burst out.

"Easy, Gregg." Snap cast a vague look around Anita's draped apartment. An open window was beside us, leading to a tiny catwalk balcony. It was moonlit now, and two hundred feet above the pedestrian viaduct.

But Snap continued to frown. "Easy, I tell you. Why shout about Halsey? The air can have ears."

Venza moved and closed and sealed the window.

"What is it?" I asked, more softly.

But Snap was not satisfied. "Anita, do you have a complete isolation barrage for this room?"

"Of course I haven't, Snap."

"Well, Gregg do you have a detector with you?"

I had none. Snap produced his little coil and indicator dial. "It's out of order, but let's see now. Shove over that chair, Gregg."

He disconnected one of the room's tube-lights and contacted with the cathode. It was a makeshift method, but as he dropped to the floor, uncoiling a little length of his wire for an external pick-up, we saw that the thing worked. The pointer on the dial-face was swaying.

"Gregg!" he muttered. "Look at that. Didn't I tell you?"

The pointer quivered in positive reaction. An eavesdropping ray was upon us.

Anita gasped, "I had no idea!"

"No, but I did." Snap added softly. "No one very close."

He and I carried the detector to the length of the hall. The indicator went nearer normal. "It must be the other way," I whispered.

We went to the moonlit balcony. "Way down there on the pedestrian arcade," I said.

"We'll soon fix that," Snap said.

Inside the room, we made connection with a newscaster's blaring voice. Under cover of it we could talk. Snap gathered us close around him.

"Halsey has something important, and it's about this interstellar invader. It all connects. His office paged me on a public mirror. I happened to see it at Park-Circle 40. When I answered it, Halsey's man wanted me to talk in code. I can't talk in code; I have enough to worry about with the interplanetary helios. Then they sent me to an official booth, where I got examined for positive legal identification, and then they put me on the official split-wave length. After all of which precautions I was told to be at Halsey's office tonight at midnight, and told a few other things."

"What?" demanded Venza breathlessly.

"Only hints. Why take chances, by repeating them now?"

"You said he wants me, too?" I put in.

"Yes. You and Venza. We've got to get into his office secretly, by the vacuum cylinders. We're to meet a man from his office at the Eighth Postal switch-station."

"Venza?" Anita said sharply. "What in the universe can he want with Venza? If she's going, I'm going too!"

Snap gazed at her and grinned. "That sounds like a logical deduction. Naturally he must want you; that's why he said Venza."

"I'm going," Anita insisted.

We left half an hour before midnight. The girls were both in gray, with long capes. We took the public monorail into the mid-Manhattan section under the city roof of the business district, and into the Eighth Postal switch-station where the sleek bronze cylinders came tumbling out of the vacuum ports to be re-routed and dispatched again.

A man was on the lookout for us. "Daniel Dean and party?"

"Yes. We were ordered here."

The detective gazed at the girls and at me. "It was three, Dean."

"And now it's four," said Snap cheerfully. "The extra one is Miss Anita Prince. Ever heard of her?"

He had indeed. "All right," he said. "If you and Haljan say so."

We were put into one of the oversized mail cylinders and routed through the tubes like sacks of recorded letters; in ten minutes, with a thump that knocked the breath out of all of us, we were in the switch-rack of Halsey's outer office.

We clambered from the cylinder. Our guide led us down one of the gloomy metal corridors. It echoed with our tread.

A door lifted.

"Daniel Dean and party."

The guard stood aside. "Come in."

The door slid down behind us. We advanced into the small blue-lit apartment, steel-lined like a vault.

2

Colonel Halsey sat at his desk, with a few papers before him and a bank of instrument controls at his elbow. He pushed his audiphone and mirror-grid to one side.

"Sit down, please." He gave us each the benefit of a welcoming smile, and his gaze finished upon Anita.

"I came because you sent for Venza," Anita said quickly. "Please, Colonel Halsey, let me stay. I thought, whatever you want her for, you might need me, too."

"Quite so, Miss Prince. Perhaps I shall." It seemed that in his mind were many of the thoughts thronging my own, for he added: "Haljan, I recall I sent for you like this once before. I hope this may be a more auspicious occasion."

"So do I, sir."

Snap said, "We've been afraid hardly to do more than a whisper. But you're insulated here, and we're mighty curious."

Halsey nodded. "I can talk freely to you, and yet I cannot." His gaze went to Venza. "It is you in whom I am most interested."

"Me? You flatter me, Colonel Halsey." She sat gracefully reclining in the metal chair before his desk, seeming small as a child between its big, broad arms. Her long gray skirt had parted to display her shapely, gray-satined legs. She had thrown off the hood of her cloak. Her thick black hair was coiled in a knot low at the back of her neck; her carmine lips bore an alluring smile. It was all instinctive. To this girl from Venus it came as naturally as she breathed.

Halsey's gray eyes twinkled. "Do not look at me quite like that, Miss Venza, or I shall forget what I have to say. You would get the better of me; I'm glad you're not a criminal."

"So am I," she declared. "What can I do for you, Colonel Halsey?"

His smile faded at once. His glance included us all. "Just this. There is a man here in Greater New York, a Martian whom they call Set Molo. He has a younger sister, Setta Meka. Have any of you heard of them?"

We had not. Halsey went on, slowly now, apparently choosing his words with the greatest care. "There are things that I can tell you and there are things that I cannot."

"Why not?" asked Venza.

"My dear, for one thing, if you are going to help me you can do it best by not knowing too much. For another, I have my orders; this thing concerns the very highest authorities, not only of the U.S.W., but in Ferrok-Shahn and Grebhar too."

He paused, but none of us spoke. Then Halsey said quietly, "Well, this Martian and his sister are here now in Greater New York. They have some secret. They are engaged in some activity, and I want to find out what it is. I have picked up only little parts of it."

He stopped; and out of the silence Snap said, "If you don't mind, Colonel Halsey, it seems to me you are mostly talking in code."

"I'm not, but I'm trying to tell you as little as possible. You, Miss Venza, need only understand this: the Martian, Molo, must be induced to give you some idea of what he is doing here."

"And I am to induce him?" Venza asked calmly.

"That is my idea." The faint shadow of a smile swept Halsey's thin, intent face. "My dear, you are a girl of Venus. More than that, you have far more than your normal share of wits and brains."

It did not make Venza smile. She sat tense now, with her dark-eyed gaze fastened on Halsey's face. Anita, equally breathless,