said. His voice was dull and flat, without tone and without spirit. A muscle in Neff's cheek was twitching.

"I don't understand you," Thompson said.

"Hell, you understand me well enough. The facts are obvious. We've either all got the virus, or it's here in the ship, and we will get it. All we're doing is waiting to see who goes next. What I want to know is—Who'll shove the last man through the ejection port?"

"I don't know," Thompson answered.

"Isn't there anything else we can do?" The tic in Neff's cheek was becoming more pronounced.

"If there is, I don't know—What the hell, Buster?" The cat which had been lying in his lap, suddenly leaped to the floor. Tail extended, crouched, eyes alert, the cat seemed to be trying to follow the flight of something through the air above him.

Very vaguely, very dimly, Thompson caught the rustle of wings.

The actions of the cat, and the sound, sent a wave of utter cold washing over his body.

Before he could move, the cat leaped upward, caught something in snapping jaws.

In the same split second Thompson moved. Before Buster had had time to swallow, Thompson had caught him behind the jaws, forcing them shut. On his desk was a bell jar. He lifted it, thrust the cat's head under it, forced his thumb and forefinger against the jaws of the cat.

The outraged Buster disgorged something. Thompson jerked the cat's head from under the jar, slammed down the rim. The angry cat snarled at him. Neff and Fortune were staring at him from eyes that indicated they thought he had lost his senses. Thompson paid them no attention. He was too busy watching something inside the bell jar even to notice that they existed.

He could not see the creature under the jar.

He knew it could fly but he did not know its shape or size. He could hear it hitting the falls of the jar. And each time it hit the wall, a tiny greenish smudge appeared at the point of impact.

"What—what the hell have you got there?" Neff whispered.

"I don't know for sure. But I think I've got the carrier of the virus."

"What?"

"Watch."

"I can't see anything."

"Nor can I yet, but I can hear it and I can see the places where it hits the wall of the jar. There's something under the jar. Something that Buster has been seeing all along."

"What?"

Thompson pointed at the jar. "One or several of those things came into the ship when the lock was open. We couldn't see them, didn't know they existed. But Buster saw them. He caught one of them in this cabin soon after we took off. I thought he was playing a game to amuse himself, or—" He broke off. From the back of his mind came a fragment of history, now in the forgotten Dark Ages of Earth, whole populations had been ravaged and destroyed by a fever that was carried by some kind of an insect. Did they have some kind of an insect under his jar?

Holding his breath, Thompson watched.

The pounding against the walls of the jar was growing weaker. Then it stopped. On the desk top, a smudge appeared. Wings quavered there, wings that shifted through a range of rainbow colors as they became visible.

As the flutter of the wings stopped the whole creature became visible. Made up of some kind of exceedingly thin tissue that was hardly visible, it was about as big as a humming bird.

Silence held the room. Thompson was aware of his eyes coming to focus on the long pointed bill of the creature.

"Alive it was not visible at all," Fortune whispered. "Dead, you can see it." His voice lifted, picked up overtones of terror. "Say an hour or so ago Ross was complaining that something had bit him."

Like the last remnant of a picture puzzle fitting together, something clicked in Thompson's mind. "And Kurkil. While we were out of the ship something bit him."

Silence again. His eyes went from Neff to Fortune. "Did—"

They shook their heads.

"Then that ties up the package," Thompson whispered. "This creature carried the