The main thing is not to lose your head.
Watch your neighbor, but don't jump to conclusions. Be sure before you
act."

There was a stir and Gallifa paused. The doctor pushed his way through
the men to the front of the room. His face was white and haggard.

"What about the tests?" Gallifa asked.

"There aren't going to be any tests," Dr. Thorndyke replied grimly. "At
least not on the men in the hospital. They are all dead."

"What happened?" Gallifa urged, his eyes wide with shock.

Everyone was very quiet.

The doctor wiped his hand across his forehead. "Nolan was on duty in the
wardroom. He went out for a smoke. I heard him go out. I didn't hear him
come back. I was setting up some new equipment. When I finally went back
to the ward Nolan must have caught--whatever it is. He was gone, and
he'd slit every man's throat with a scalpel."

Gallifa faced the assemblage. "We're going to inoculate everyone here.
As soon as we're through, I want each team to go to their own shacks and
stay there. If you _have_ to go somewhere, go in pairs. If you see
anyone wandering around by himself, no matter _who_ he is, bang him over
the head with something and bring him over to the hospital. Otherwise,
stay put."

The men received their shots in an uncomfortable silence and disappeared
into the night. Gallifa, MacFarland, and Dr. Thorndyke remained in the
Administration room.

"Any idea what it is, doc?" MacFarland asked huskily.

"I hardly had time to take care of the patients," Dr. Thorndyke replied
bitterly. "Did you honestly expect me to find out what was wrong with
them in a few short hours?"

"But--" Gallifa began.

MacFarland suddenly started, and leapt to his feet. The doctor moved
away, his face paling.

"What's the matter?" Gallifa asked, alarmed.

"Don't be so old womanish," MacFarland snapped. "I'm not catching it. I
just thought of something. Cummings had a gun. Where did he get it?"

"The storeroom!" Gallifa exclaimed. "I'd forgotten we had weapons and
ammo in the storeroom! If things got bad enough, we _could_ wipe
ourselves out. We'd better check."

"I'm going back to the hospital," Dr. Thorndyke said bluntly. "I'm going
to lock the door. If anyone comes banging around he damn well had better
know who he is and talk intelligently--or I'll slice him from his
wishbone to his crotch." He stalked out.

Gallifa stared blankly after Dr. Thorndyke. It was funny hearing him
talk this way. He had always thoug