Jonnie had been in a coma for three days.

They had brought him to the ancient underground military base in the Rocky Mountains where salt filters could be dropped into place at once if a counterattack materialized from the planet Psychlo.

The hospital complex was very extensive. It was all white tile, hardly any of it cracked. The Russians had cleaned it all up and the parson had buried the crumbling dead.

Fifteen of the wounded Scots were there, including Thor and Glencannon. They were in a separate series of rooms from Jonnie's, but one could hear them now and then, especially when the pipe major gave them an afternoon concert. Dr. Allen and Dr. MacKendrick had already discharged five of them as reasonably well and certainly too restless and impatient to keep idle when so many things were going on elsewhere.

Chrissie had been in constant attendance at Jonnie's bedside and she rose when Dr. MacKendrick and Angus MacTavish came in. They seemed angry with one another and Chrissie hoped they would go soon. MacKendrick put a hand on Jonnie's forehead and stood there for a moment looking at the ashen pallor. Then he turned to Angus with an expressive hand that seemed to say, “See?” Jonnie's breathing was shallow.

Three days before Jonnie had awakened and whispered to her to send for somebody. There was always a Scot guard at the door, his assault rifle blocking out would-be visitors, of which there were too many. Chrissie had brought him in and watched worriedly while Jonnie whispered a long message to Robert the Fox, and the guard got it on a picto-recorder mike held close to Jonnie's lips. The message had been to the effect that if another gas drone appeared in the sky they could probably stop it by landing thirty recon drones on it with magnetic skids and racing their engines on reverse coordinates so the gas drone's motors would burn out. Chrissie didn't understand the message but she did understand that it was too tiring to Jonnie. He had relapsed back into a coma, and when the guard came back to say Sir Robert sent his thanks and would do that, Chrissie was quite cross with him.

The same guard was on again when Dr. MacKendrick and Angus were let in, and Chrissie vowed she would reason with him. MacKendrick, yes. Angus, definitely no!

MacKendrick and Angus went out and the guard closed the door behind them.

“Look,” said MacKendrick, dragging Angus into one side room after another. “Machines, machines, machines. This was once a very well appointed and outfitted hospital.

Those big things over there– I have seen them in an ancient book– were called 'X-ray machines.' It was a subject called radiology.”

“Radiation?” said Angus. “No, man, not on Jonnie! Radiation is for killing Psychlos. You're daft!”

“Those machines let you look inside the body and find out what is wrong. They were invaluable.”

“Those machines,” said Angus, angrily, “were run by electricity! Why do you think we light this place with mine lamps?”

“You must get them running!” said

MacKendrick.

“Even if I did, I see by that one they have tubes. The gas in those tubes is over a thousand years old. We can't get any more of it and couldn't get it into the tubes if we had any! You're daft, man.”

MacKendrick glared at him. “There is something pressing on his brain! I can't just go plunging into it with a scalpel. I can't guess. Not with Jonnie MacTyler!

People would slaughter me!”

“You want to see inside his head,” said Angus. “Well, why didn't you say so?” Angus went off muttering about electricity.

He told a standby pilot at the heliport that he needed to get to the compound fast. The pilots were very few and they were being run ragged. They were zipping off to all parts of the world; they had a sort of international airline going that was beginning to visit every remaining pocket of men on the planet at least once a week. They were ferrying World Federation Coordinators and chiefs and tribal leaders as fast as they could. More pilots were in training, but right now they only had thirty plus the two in hospital. So a casual request, even from a Scot, even from a member of the original combat force, was not likely to get much heed. Travel from the underground base to the compound was usually by ground car.

Angus told him it had to do with Jonnie, and the pilot said why hadn't he said so and pushed him into a plane and said he would wait for him to come back.

With grim purpose, Angus went to the compound section where they kept the captive Psychlos. A small area of the old dormitory level had been rigged to circulate breathe-gas and “unreconstructed” Psychlos were there under heavy guard. They numbered about sixty now, for occasional ones were brought here from distant minesites when they surrendered peacefully. Terl was captive elsewhere.

Angus got an air mask and the Scot guard let him in. The place was very dim and the huge Psychlos sat around in attitudes of despair. One didn't walk in the place without being covered by the guard. The prisoners expected a Psychlo counterattack and were not too cooperative.

The Scot engineer located Ker and dug him out of his apathy. He demanded of Ker to tell him whether he knew of any mining equipment that would let one look through solid objects. Ker shrugged. Angus told him who it was for and Ker sat there for a while, his amber eyes thoughtful.

Then suddenly he wanted to be reassured as to who this was for, and Angus told him it was for Jonnie. Ker was turning a tiny gold band around in his claws. Suddenly he sprang up and demanded that Angus give him an escort and a breathe-mask.

Ker went down to the shops and in a storeroom there dug up a strange machine. He explained it was used to analyze the internal structure of mineral samples and to find crystalline cracks inside metals. He showed Angus how to work it. You put the emanation tube under the object to be examined and you read the results on the top screen. There was also a trace paper reader that showed metals in alloys or rocks. It worked on some wavelength he called sub-proton field emanation, and this was intensified by the lower tube, and the influence went through the sample and you read it on the top screen. Being Psychlo, it was quite massive, and Ker carried it for him to the waiting plane. A guard took Ker back and Angus returned to the military base.

They tried it with some cats they had that were cleaning the rat population out, and the cats afterward seemed cheerful enough. The screen showed the skull outline very nicely. They tried it on one of the wounded Scots who volunteered and they found a piece of stone in his hand from a mine injury, and he too seemed fine afterward.

About 4:00 that afternoon they used it on Jonnie. By 4:30 they had a three-dimensional picture and the trace paper.

A very relieved Dr. MacKendrick pointed it out to Angus. “A piece of metal! See it? A sliver just below one of the trephine holes. Well! We'll just get him ready and I can have that out with a scalpel soon enough!”

“Metal?” said Angus. “Scalpel? On Jonnie? No you don't! Don't you dare touch him! I’ll be right back!”

With the metal trace paper flying behind him, Angus fifteen minutes later charged in on the Chamco brothers. They worked in a separate breathe-gas dome at the compound, industriously trying to assist Robert the Fox to put things back together.

Angus shoved the trace under their pug nosebones: “What metal is this?”

The Chamcos examined the trace squiggles. “Ferrous daminite," they said. “A very strong support alloy.”

“Is it magnetic?” demanded Angus. And they said yes, of course it was.

By six o'clock Angus was back in the hospital. He had a heavy electrocoil he had just made. It had handgrips on it.