before them. His eyes burned.

“Giving him a clear picture, eh?” he rasped. “Letting him spy out everything?”

Baird pressed the communicator call for the radar room and said coldly:

“I’m obeying orders. Look, Taine! You were picked for your job because you were a xenophobe. It helps in your proper functioning. But this Plumie is here under a flag of truce—”

“Flag of truce!” snarled Taine. “It’s vermin! It’s not human! I’ll—”

“If you move one inch nearer him,” said Baird gently, “just one inch—”

The skipper’s voice bellowed through the general call speakers all over the ship:

“Mr. Taine! You will go to your quarters, under arrest! Mr. Baird, burn him down if he hesitates!”

Then there was a rushing, and scrambling figures appeared and were all about. They were members of the Niccola’s crew, sent by the skipper. They regarded the Plumie with detachment, but Taine with a wary expectancy. Taine turned purple with fury. He shouted. He raged. He called Baird and the others Plumie-lovers and vermin-worshipers. He shouted   foulnesses at them. But he did not attack.

When, still shouting, he went away, Baird said apologetically to the Plumie:

“He’s a xenophobe. He has a pathological hatred of strangers—even of strangeness. We have him on board because—”

Then he stopped. The Plumie wouldn’t understand, of course. But his eyes took on a curious look. It was almost as if, looking at Baird, they twinkled.

Baird took him back to the skipper.

“He’s got the picture, sir,” he reported.

The Plumie pulled out his sketch plate. He drew on it. He offered it. The skipper said heavily:

“You guessed right, Mr. Baird. He suggests that someone from this ship go on board the Plumie vessel. He’s drawn two pressure-suited figures going in their air lock. One’s larger than the other. Will you go?”

“Naturally!” said Baird. Then he added thoughtfully: “But I’d better carry a portable scanner, sir. It should work perfectly well through a bronze hull, sir.”

The skipper nodded and began to sketch a diagram which would amount to an acceptance of the Plumie’s invitation.

This was at 07 hours 40 minutes ship time. Outside the sedately rotating metal hulls—the one a polished blue-silver and the other a glittering golden bronze—the cosmos continued to be as always. The haze from explosive fumes and rocket-fuel was, perhaps, a little thinner. The brighter stars shone through it. The gas-giant planet outward from the sun was a perceptible disk instead of a diffuse glow. The oxygen-planet to sunward showed again as a lighted crescent.

Presently Baird, in a human spacesuit, accompanied the Plumie into the Niccola’s air lock and out to emptiness. His magnetic-soled shoes clung to the Niccola’s cobalt-steel skin. Fastened to his shoulder there was a tiny scanner and microphone, which would relay everything he saw and heard back to the radar room and to Diane.

She watched tensely as he went inside the Plumie ship. Other screens relayed the image and his voice to other places on the Niccola.

He was gone a long time. From the beginning, of course, there were surprises. When the Plumie escort removed his helmet, on his own ship, the reason for the helmet’s high crest was apparent. He had a high crest of what looked remarkably like feathers—and it was not artificial. It grew there. The reason for conventionalized plumes on bronze survey plates was clear. It was exactly like the reason for human features or figures as decorative additions to the inscriptions on Space Survey marker plates. Even the Plumie’s hands had odd crestlets which stood out when he bent his fingers. The other Plumies were no less graceful and no less colorful. They had equally clear soprano voices. They were equally miniature and so devoid of apparent menace.

  But there were also technical surprises. Baird was taken immediately to the Plumie ship’s engine room, and Diane heard the sharp intake of breath with which he appeared to recognize its working principle. There were Plumie engineers working feverishly at it, attempting to discover something to repair. But they found nothing. The Plumie drive simply would not work.

They took Baird through the ship’s entire fabric. And their purpose, when it became clear, was startling. The Plumie ship had no rocket tubes. It had no beam-projectors except small-sized objects which were—which must be—their projectors of tractor and pressor beams. They were elaborately grounded to the ship’s substance. But they were not originally designed for ultra-heavy service. They hadn’t and couldn’t have the enormous capacity Baird had expected. He was astounded.

When he returned to the Niccola, he went instantly to the radar room to make sure that pictures taken through his scanner had turned out well. And there was Diane.

But the skipper’s voice boomed at him from the wall.

“Mr. Baird! What have you to add to the information you sent back?”

“Three items, sir,” said Baird. He drew a deep breath. “For the first, sir, the Plumie ship is unarmed. They’ve tractor and pressor beams for handling material. They probably use them to build their cairns. But they weren’t meant for weapons. The Plumies, sir, hadn’t a thing to fight with when they drove for us after we detected them.”

The skipper blinked hard.

“Are you sure of that, Mr. Baird?”

“Yes, sir,” said Baird uncomfortably. “The Plumie ship is an exploring ship—a survey ship, sir. You saw their mapping equipment. But when they spotted us, and we spotted them—they bluffed! When we fired rockets at them, they turned them back with tractor and pressor beams. They drove for us, sir, to try to destroy us with our own bombs, because they didn’t have any of their own.”

The skipper’s mouth opened and closed.

“Another item, sir,” said Baird more uncomfortably still. “They don’t use iron or steel. Every metal object I saw was either a bronze or a light metal. I suspect some of their equipment’s made of potassium, and I’m fairly sure they use sodium in the place of aluminum. Their atmosphere’s quite different from ours—obviously! They’d use bronze for their ship’s hull because they can venture into an oxygen atmosphere in a bronze ship. A sodium-hulled ship would be lighter, but it would burn in oxygen. Where there was moisture—”

The skipper blinked.

“But they couldn’t drive in a non-magnetic hull!” he protested. “A ship has to be magnetic to drive!”

“Sir,” said Baird, his voice still shaken, “they don’t use a magnetronic drive. I once saw a picture of the drive they use, in a stereo on the history of space travel. The principle’s very old. We’ve practically forgotten it.   It’s a Dirac pusher-drive, sir. Among us humans, it came right after rockets. The planets of Sol were first reached by ships using Dirac pushers. But—” He paused. “They won’t operate in a magnetic field above seventy Gauss, sir. It’s a static-charge reaction, sir, and in a magnetic field it simply stops working.”

The skipper regarded Baird unwinkingly for a long time.

“I think you are telling me,” he said at long last, “that the Plumies’ drive would work if they were cut free of the Niccola.”

“Yes, sir,” said Baird. “Their engineers were opening up the drive-elements and checking them, and then closing them up again. They couldn’t seem to find anything wrong. I don’t think they know what the trouble is. It’s the Niccola’s magnetic field. I think it was our field that caused the