"No, no," the voice — her voice — reassures her. "You are correct — I am using your speech apparatus. Please forgive me; I have none of my own that you could hear."
Coati digests this dubiously. If this is a hallucination, it's really complex. She's never done anything like this before. Could it be real, some kind of alien telekinesis?
"But where are you? Why don't you come out and show yourself?"
"I can't. I will explain. Please promise me you won't be frightened. I have damaged nothing, and I will leave anytime you desire."
Coati suddenly gets an idea, and eyes the computer sharply. In fantasy shows she's seen holos about alien minds taking over computers. So far as she knows, it's never happened in reality. But maybe—
"Are you in my computer?"
"Your computer?" Incredibly, the voice gives what might almost be a giggle. "In a way, yes. I told you I am very, very small. I am in empty places, in your head." Quickly it adds, "You aren't frightened, please? I can go out anytime, but then we can't speak."
"In my head!" Coati exclaims. For some reason she, too, feels like laughing. She knows she should be making some serious response, but all she can think of is, this is why her sinuses feel stuffy. "How did you get in my head?"
"When you rescued me I was incapable of thought. We have a primitive tropism to enter a body and make our way to the head. When I came to myself, I was here. You see, on my home we live in the brains of our host animals. In fact, we are their brains."
"You went through my body? Oh — from that place on my arm?"
"Yes, I must have done. I have only vague, primitive memories. You see, we are really so small. We live in what I think you call intermolecular, maybe interatomic spaces. Our passage doesn't injure anything. To me, your body is as open and porous as your landscape is to you. I didn't realize there was so much large-scale solidity around until I saw it through your eyes! Then, when you went cold, I came to myself and learned my way around, and deciphered the speech centers. I had a long, long time. It was …lonely. I didn't know if you would ever awaken…"
"Yeah…." Coati thinks this over. She's pretty sure she couldn't imagine all this. It must be real! But all she can think of to say is, "You're using my eyes, too?"
"I've tapped into the optic nerve, at the second juncture. Very delicately, I assure you. And to your auditory channels. It's one of the first things we do, a primitive program. And we make the host feel happy, to keep from frightening it. You do feel happy, don't you?"
"Happy? — Hey, are you doing that? Listen, if that's you, you're overdoing it! I don't want to feel quite so 'happy,' as you call it. Can you turn it down?"
"You don't? Oh, I am sorry. Please wait — my movements are slow."
Coati waits, thinking so furiously about everything at once that her mind is a chaos. Presently there comes a marked decrease in the distracting physical glow. More than all the rest, this serves to convince her of the reality of her new inhabitant.
"Can you read my mind?" she asks slowly.
"Only when you form words," her own voice replies. "Subvocalizing, I think you call it. I used all that long cold time tracing out your vocabulary and language. We have a primitive drive to communication; perhaps all life-forms have."
"Acquiring a whole language from a static, sleeping brain is quite a feat," says Coati thoughtfully. She is beginning to feel a distinct difference in her voice when the alien is using it; it seems higher, tighter — and she hears herself using words that she knows only from reading, not habitual use.
"Yes. Luckily I had so much time. But I was so dismayed and depressed when it seemed you'd never awaken. All that work would be for nothing. I am so happy to find you alive! Not just for the work, but for — for life. …Oh, and I have had one chance to practice with your species before. But your brain is quite different."
However flustered and overwhelmed by the novelty of all this, Coati isn't stupid. The words about "home" and "hosts" are making a connection with Boney and Ko's report.
"Did the two men who sent that message you were riding on visit your home planet? They were two Humans— that's what I am — in a ship bigger than this."
"Oh, yes! I was one of those who took turns being with them! And I was visiting one of them when they left." …The voice seems to check itself. "Your brain is really very different."
"Thanks," says Coati inanely. "I've heard that those two men — those two Humans — weren't regarded as exactly bright."
'Bright?' Ah, yes. …We performed some repairs, but we couldn't do much."
Coati's chaotic thoughts coalesce. What she's sitting here chatting with is an alien — an alien who is possibly deadly, very likely dangerous, who has invaded her head.
"You're a brain parasite!" she cries loudly. "You're an intelligent brain parasite, using my eyes to see with and my ears to hear with, and talking through my mouth as if I were a zombie — and, and for all I know, you're taking over my whole brain!"
"Oh, please! P-please!" She hears her own voice tremble. "I can leave at any moment — is that what you wish? And I damage nothing — nothing at all. I use very little energy. In fact, I have cleared away some debris in your main blood-supply tube, so there is more than ample for us both. I need only a few components from time to time. But I can withdraw right now. It would be a slow process, because I've become more deeply enmeshed and my mentor isn't here to direct me. But if that's what you want, I shall start at once, leaving just as I came. …Maybe— n-now that I'm refreshed, I could survive longer, clinging to your ship."
The pathos affects Coati; the timbre of the voice calls up the image of a tiny, sad, frightened creature shivering in the cold prison of space.
"We'll decide about that later," she says somewhat gruffly. "Meanwhile I have your word of honor you aren't messing up my brain?"
"Indeed not," her own voice whispers back indignantly. "It is a beautiful brain."
"But what do you want? Where are you trying to go?"
"Now I want only to go home. I thought, if I could reach some central Human place, we could find someone who would carry me back to my home planet and my proper host."
"But why did you leave Boney and Ko and go with that message pipe in the first place?"
"Oh — I had no idea then how big the empty spaces are; I thought it would be like a long trip out-of-body at home. Brrr-rr! There's so much I don't know. Can you tell that I am quite a young being? I have not at all finished my instructions. My mentors tell me I am foolish, or foolhardy. I–I wanted adventure?" The little voice sounds suddenly quite strong and positive. "I still do, but I see I must be better prepared."
"Hmm. Hey, can you tell I'm young, too? I guess that makes two of us. I guess I'm out here looking for adventure, too."
"You do understand."
"Yeah." Coati grins, sighs. "Well, I can carry you back to FedBase, and I'm sure they'll be sending parties to your planet soon. It's a First Contact for us, you know; that's what we call meeting a new non-Human race. We know about fifty so far, but no one just like you. So I'm certain people will be going."
"Oh, thank you! Thank you so much."
Coati feels a surge of physical pleasure, an urge—
"Hey, you're doing that again! Stop it."
"Oh, I am sorry." The glow fades. "It's a primitive response to gratitude. To give pleasure. You see, our normal hosts are quite mindless; they can be thanked only by physical sensation."
"I see." Pondering this, Coati sees something else, too. "I suppose you could make them feel pain, too, to punish them, if they did something you didn't like?"