We started out with her very early life. Each record started with the subject-Mary, that is-choking and groaning and struggling the way people always do when they are being forced back on a memory track which they would rather not follow, then would come the reconstruction, both in Mary's voice and in other voices. What surprised me most was Mary's face-in the tank, I mean. We had the magnification stepped up so that the stereo image of her face was practically in our laps and one could follow every change of expression.

First her face became that of a little girl-oh, her features were the same grown-up features but I knew that I was seeing my darling as she must have been when she was very small. It made me hope that we would have a little girl ourselves.

Then her expression would change to match when other actors out of her memory took over. It was like watching an incredibly able monologist playing many parts.

Mary took it with apparent serenity but her hand stole into mine. When we came to the terrible part when her parents changed, became not her parents but slaves of slugs, she clamped down on my fingers so hard that it would have crushed a hand less hamlike than my own. But she controlled herself.

I skipped over the spools marked "period of suspended animation". I was surprised to find that there were a great many of them; I would have thought that there was nothing to dig out of the memory of a person in such a condition. Be that as it may, I could not see how she could have learned anything during that period which would tell us how the slugs had died, so I left them out and proceeded to the group concerned with the time from her resuscitation to the group concerned with her rescue from the swamps.

One thing was certain from her expressions in the imaged record: she had been possessed by a slug as soon as she was revived. The dead quality of her face was that of a slug not bothering to keep up a masquerade; the stereocasts from Zone Red were full of that expression. The barren qualities of her memories from that period confirmed it.

Then, rather suddenly, she was no longer hag-ridden but was again a little girl, a very sick and frightened little girl. There was a delirious quality to her remembered thoughts, but, at the last, a new voice came out loud and clear; "Well, skin me alive come Sunday! Look, Pete-it's a little girl!"

Another voice answered, "Alive?" and the first voice answered, "I don't know."

The rest of that tape carried on into Kaiserville, her recovery, and many new voices and memories; presently it ended.

"I suggest," Dr. Steelton said as he took the tape out of the projector, "that we play another one of the same period. They are all slightly different and this period is the key to the whole matter."

"Why, Doctor?" Mary wanted to know.

"Eh? Of course you need not see them if you don't want to-but this period is the one which we are actually investigating. From your memories we must build up a picture of what happened to the parasites on Venus, why they died. In particular, if we could tell just what killed the titan which, uh, possessed you before you were found-what killed it and left you alive-we might well have the weapon we need."

"But don't you know?" Mary asked wonderingly.

"Eh? Not yet, not yet-but we'll get it. The human memory is an amazingly complete record, even though unhandy to use."

"But I can tell you now-I thought you knew. It was 'nine-day fever'."

"What?" Hazelhurst was out of his chair as if prodded.

"But of course. Couldn't you tell from my face? It was utterly characteristic-the mask, I mean. I saw it several times; I used to nurse it back ho-back in Kaiserville, because I had had it once and was immune to it."

Steelton said, "How about it Doctor? Have you ever seen a case of it?"

"Seen a case? No, I can't say that I have; by the time of the second expedition they had the vaccine for it. I'm thoroughly acquainted with its clinical characteristics, of course."

"But can't you tell from this record?"

"Well," Hazelhurst answered carefully, "I would say that what we have seen is consistent with it-but not conclusive, not conclusive."

"What's not conclusive?" Mary said sharply. "I told you it was 'nine-day fever'."

"We must be sure," Steelton said apologetically.

"How sure can you get? There is no question about it. I was told that I had had nine-day fever, that I had been sick with it when Pete and Frisco found me. I nursed other cases later and I never caught it again. I remember what their faces looked like when they were ready to die-just like my own face in the record. Anyone who has ever seen a case never forgets it and could not possibly mistake it for anything else. What more do you want? Fiery letters in the sky?" I have never seen Mary so close to losing her temper-except once. I said to myself: look out, gentlemen, better duck!

Steelton said, "I think you have proved your point, dear lady-but tell me: you were believed to have no memory of this period and my own experience with you leads me to think so. Now you speak as if you had direct, conscious memory-yes?"

Mary looked puzzled. "I remember it now-I remember it quite clearly. I haven't thought about it in many years."

"I think I understand." He turned to Hazelhurst. "Well, Doctor? Do we have a culture of it in the laboratory? Have your boys done any work on it?"

Hazelhurst seemed stunned. "Work on it? Of course not! It's utterly out of the question-nine-day fever! We might as well use polio-or typhus. I'd rather treat a hangnail with an ax!"

I touched Mary's arm and said, "Let's go, darling. I think we have done all the damage we can." As we left I saw that she was trembling and that her eyes were full of tears. I took her into the messroom for systemic treatment-distilled.

Later on I bedded Mary down for a nap and sat with her until I was sure she was asleep. Then I looked up my father; he was in the office they had assigned to him. The green privacy light was already on. "Howdy," I said.

He looked at me speculatively. "Well, Elihu, I hear that you hit the jackpot."

"I prefer to be called 'Sam'," I answered.

"Very well, Sam. Success is its own excuse; nevertheless the jackpot appears to be disappointingly small. The situation seems to be almost as hopeless as before. Nine-day fever, no wonder the colony died out and the slugs as well. I don't see how we can use it. We can't expect everyone to have Mary's indomitable will to live."

I understood him; the fever carried a 98-percent plus death rate among unprotected Earthmen. With those who had taken the shots the rate was an effective zero-but that did not figure. We needed a bug that would just make a man sick-but would kill his slug. "I can't see that it makes much difference," I pointed out. "It's odds-on that you will have typhus-or plague-or both-throughout the Mississippi Valley in the next six weeks."

"Or the slugs may have learned a lesson from the setback they took in Asia and will start taking drastic sanitary measures," he answered. I had not thought of that; the idea startled me so that I almost missed the next thing he said, which was: "No, Sam, you'll have to devise a better plan than that."

"I'll have to? I just work here."

"You did once-but now you've taken charge. I don't mind; I was ready to retire anyhow."

"Huh? What the devil are you talking about? I'm not in charge of anything-and don't want to be. You are head of the Section."

He shook his head. "A boss is the man who does the bossing. Titles and insignia usually come after the fact, not before. Tell me-do you think Oldfield could take over my job?"

I considered it and shook my head; Dad's chief deputy was the executive officer type, a "carry-outer", not a "think-upper". "I've known that you would take over, some day," he went on. "Now you've done it-by bucking my judgment on an important matter, forcing your own on me, and by being justified in the outcome."