Had Aftran's nothlit body been human, it would have been an effort for her not to raise her eyebrows at Cassie's words. Being a whale, though, her face and body gave no indication of her reaction.

Infestation. She would have to go through it, in order to regain her own form and receive a host. To inhabit Cassie again, who had told her only moments earlier that she wanted to be Aftran's host. At least, for a little while.

Yes, Cassie had said that she would protect Aftran from this stipulation. Because Peace Movement Yeerks were exempt, and hadn't Aftran been a founder of the Movement? Hadn't she been willing to give her life for the cause?

But no. It wouldn't be right to bypass this requirement. After all, all of her previous hosts had been involuntary-well, except for the Gedd she had infested as her first host. Most of the Gedds were, or at least cooperative, having been used as hosts for as long as their species had existed. The oldest Yeerks that Aftran had known told stories of the home planet, how the original relationship between Gedds and Yeerks was entirely symbiotic, how the early Yeerks often didn't even take full control of their Gedds. That, back before Seerow had come, most Yeerks didn't even desire to infest a host-or at least, not long term.

Still. Nearly all of the Hork-Bajir were involuntary, and certainly the one she had infested while she had been on Visser Three's personal guard. Karen had been involuntary. Cassie-it was hard to classify Cassie. The first time, the young human had forced Aftran inside her head, which were far from the actions of an involuntary host. But, it was clear that she did not want to be a host to Aftran long term. Not if she could help it. The second time, after she had saved Aftran from the visser, she had offered Aftran residence in her mind. Aftran had refused, stating that it would put everyone in too much danger. Cassie would have to return to the Yeerk Pool every three days. Besides, how could she fight a war against Yeerks, killing Yeerks, with a Yeerk in her head?

Aftran may have done a lot for the Peace Movement, but she had taken unwilling hosts. She should experience infestation firsthand. It was only right.

(Cassie, I don't want them to make an exception for me,) she told the now adult human woman.

Cassie sighed. "Do you want to know how it will work?"

(How infestation works? I have a general idea of that,) Aftran replied, sardonically.

Cassie managed a laugh. "There are humans with Yeerk morphs. Usually, members of our military. After you've regained your form, they will hold your body over a sample of a human DNA mix. You concentrate on it, and acquire it. Unlike regular human morphs, though, this one disappears from your bloodstream after twenty-four hours."

(Why's that?) Aftran wondered.

"There are only so many samples that they could make, and besides, the government thought that it would be too dangerous for multiple copies of the same DNA mixture to be made available to millions of Yeerks. You know how the Animorphs and I wouldn't morph sentient beings without their consent?" Cassie asked.

(Yes, of course,) Aftran recalled. (It stems from this, then?)

"Right. There's a procedure for Yeerks to obtain the DNA of humans, officially, but it can take weeks to be completed. So, we have temporary DNA for temporary infestation purposes," Cassie continued. "All of the people who gave their DNA for the morph mixes gave consent, but only under these terms."

(After I receive the DNA mix and morph, what happens?)

"A member of the military will morph Yeerk and infest you. They will be required to stay in your head for one hour and fifty minutes. They are expected to search your memories fully during that time, and take full control. They're not supposed to use mental torture-but there's no way to check this out, unless the Yeerk who's been infested wants to go through this again with another member of the military. The point, as you probably figured out, is to put the Yeerk through the experience of infestation, to have their memories examined and their bodies taken away. Like they did to their hosts," Cassie told Aftran. "It's monitored-well, to an extent. No one except the Yeerk and the member of the military can know what goes on inside their heads, but it takes place in a secured room, and there are other military members there to make sure that it doesn't go on for more than the allotted hour and fifty minutes. After that, they both demorph, and the member of the military will record what he-or she-has seen. If there's been anything that would have disqualified the Yeerk for gaining nothlit status in the beginning, like severe host torture or other war crimes, than the Yeerk has to either remain a Yeerk for the rest of their life, or become a nothlit again, but in an animal form of their choosing."

(How often has this happened since you began?)

"Out of over a thousand-none so far."

(Well, that's good, isn't it? Yeerks can experience the other side of infestation, and it will make them think twice about taking control or opening their host's memories when they haven't been given consent. It must make them more empathetic to the entire process,) Aftran speculated.

"I have no problems with the process," Cassie replied, firmly. "But I don't want you to go through it."

Aftran let out a thought speech sigh. (I can handle it.)

"You shouldn't have to," Cassie insisted.

Another sigh. (You don't need to protect me, Cassie. If I'm going to live in your head, I should experience it for myself.)

Truth be told, though, the idea of a stranger from the United States military prowling around in her head, searching all of her memories, taking control of her body...it made her ill.

Still. It would be less than two hours. She'd controlled her involuntary hosts for far longer than that.

It was, Aftran supposed, a form of penance. Of making atonement. She should suffer some discomfort, for what she had done to others.

On the other hand...perhaps, it would be more equal, especially since Cassie wanted Aftran back in her head, if Cassie was the one who morphed Yeerk and infested Aftran.

This would bring a form of poetic justice, of fairness, to the entire process.

(Could you do it?) Aftran asked, averting her eyes away from Cassie, speaking so quietly that she wasn't sure if the human had heard her.

She heard Cassie take a deep breath.

"If you want me to. If I can get permission for it to be me." Then, Cassie laughed, a little. "The second part shouldn't be too difficult."

(No, I suppose not,) Aftran remarked, hoping that humor transferred over her words. (You are, after all, only one of the humans who saved the world from the Yeerk empire.)

Cassie managed a laugh. Aftran could tell that it was forced.

"If that's what you really want," she repeated. "I've morphed Yeerk before, but only infested one person, and only for a little while. I didn't know what I was doing then..."

(It's not too difficult, once you relax into the instincts,) Aftran reassured Cassie. (I can certainly walk you through it, once you're in my mind.)

A nod. "You're sure, Aftran?"

(I'm sure.)

During the week that followed, Aftran stayed close to the coast in her whale form. Cassie needed to receive permission, and the process of administering the injection to Aftran as a whale would be slightly more complicated than it would be had she been a human.

Only slightly, of course.

Of the Yeerks that had chosen to become nothlit animals, most stuck to land based ones. Even though humpback whales could live up to a hundred years, many Yeerks preferred to have wings. This meant that the Yeerks who had become birds were, if not already dead, certainly approaching the last stage of their life. How incredible it must have been to hear the message. To be given more years at life, and in addition to that, the promise of maybe having a voluntary host. As long as they agreed to morph human and be infested, first.

It also meant that the process of administering the injection would be fairly simple. Simply fly to one of the bases, wait in a room for a few hours, and come out as a Yeerk.

For Aftran, who depended on the water for her livelihood, the injection would have to be administered by boat. Moreover, she would have to spend the entire time trapped under a large net-a tarp, really-because once she began to shrink, it would be up to the humans to catch her and place her in a glass of freshwater.

Salt water did not kill Yeerks upon contact, but she had heard that it was painful after a few minutes of exposure.

Aftran was glad, after Cassie and the others had explained all of this to her, that they cared enough to take these precautions.

(Will you be there the entire time?) she asked Cassie, once she was settled under the tarp. Well, not settled, exactly. It was downright uncomfortable. But, it was the best way for them to go about this without causing any damage to her Yeerk form.

Aftran felt the human's hand on her body. "Yes."

She felt the needle go into her body. It was much larger than a normal human one, because they had to ensure that the medicine went into her bloodstream. The pain was sharp, but it dulled after a minute.

She waited. And waited.

It would take two hours for the antidote-as she thought of it-to begin to work. Two hours of lying on the tarp, the rough material rubbing at her body. Cassie would tell her every fifteen minutes how much time had passed. Otherwise, they remained silent with each other. There was no privacy, after all, not with the others there, and while Aftran didn't distrust them, she didn't want to say anything to the human that they would overhear and-quite possibly-repeat. Granted, Aftran could speak in thought speech, but Cassie couldn't reply in the same way, so it didn't seem entirely fair.

An hour in, one of the men emptied krill into her tarp.

"Thought you might be hungry," he said, grinning.

She was.

(Thank you,) she said, before eating.

It also helped to pass the time.

"Two hours," Cassie finally announced.

As soon as she had finished speaking, the changes began. Aftran was glad for the warning, because having only morphed once on her own before, it was a new and terrifying experience. At first, her sight vanished. Then, she felt her body shrink. She tried not to scream as the other changes occurred although, she realized later, she probably had more in common with her Yeerk body in her whale body than had she been a human or land based animal making the same change.

At last, it was over. She knew this instinctively, but she also knew because she felt herself being lifted up. Perhaps, it was Cassie doing the lifting. She hoped it was.

Fresh water enveloped her. The lack of sight should have felt familiar to Aftran, but it had been so long since she had been a Yeerk that the blindness terrified her. She reminded herself it was only temporary. Soon, she would be at the base. They would give her DNA from a human mix. She would receive eyes again. Arms. Legs. A body.

And then, Cassie would infest her for nearly two hours.