"The passage of a liquid through a semi-permeable membrane," Max rattled off, half-engrossed in other thoughts. "It was first discovered by French botanist Henri Dutrochet.

"Got it in one," Liz nodded, then noticed the far-away look on his face. "Max? What's wrong?"

"Nothing ... I just ..." He sighed, and closed his binder. "Have you noticed anything strange about Michael lately?"

"That's a fairly loaded question," Liz smiled.

"I mean, apart from the usual," Max replied, allowing himself a small smile. "Have you noticed anything ... different ... about him?"

Alarm bells went off in Liz's head. "Dif-different? Like how, different?"

"Like ..." Max stole a quick glance around the empty science classroom, "Like, he can't do certain things he used to do anymore. Like a part of him doesn't work any more."

Liz felt a faint blush ignite her cheeks. "You mean like--"

"No," Max interrupted quickly. "Not that. I meant his powers. He can't seem to use them anymore. It's like they're gone."

Instantly, the colour of Liz's face drained from deep red to pale white. "Gone? But ... how?"

"I don't know," Max replied. "It's like they just vanished into thin air. I'm really worried about him." Liz flinched as he spoke, which didn't go unnoticed. "Liz ... what?"

"Nothing," she shook her head, looking away. Max continued to look at her strangely, and she eventually met his eyes with her own, full of guilt. "Okay. You know I can't hide things from you. And I don't want you to worry. But you have to promise me you won't tell Michael."

"Liz?" Max looked concerned now.

"Max, promise."

"Okay," he answered softly. "I promise. Now, what's wrong?"

She sighed. "Michael's powers didn't vanish into thin air. They sort of vanished into ... Maria."

"What?" Max couldn't believe his ears. "Maria? How is that poss--"

"I don't know," Liz interrupted. "But for the past couple of days, she's been able to do these ... things. She healed my paper cut, and she changed the molecular structure of a fork into a spoon. And she can dreamwalk."

Max's face was incredulous as he absorbed what she was telling him. "But how?" He stared blankly at the cover of Liz's biology textbook.

She shrugged, shaking her head. "We have no idea. I mean, I've tried to come up with a valid hypothesis, but it just doesn't make sense. You can't catch someone's powers from them the way you'd catch a cold, as if they were contagious or something. But somehow, that's exactly what happened. Michael's powers transferred from his body and into Maria's."

Max frowned, bewildered. It didn't make any sense -- how could it even be possible? He stared blankly at his biology textbook, trying to come up with some logical rationalization for what Liz had told him, when an idea hit him.

"Osmosis."

"Osmosis?" Liz looked puzzled.

He nodded thoughtfully, still staring at the book. "It's a possibility. If you think of Michael's powers as some sort of energy, along the same parallel as a liquid, and their bodies as semi-permeable membranes ..."

"Oh my God ..." she murmured, then the implication of Max's theory hit her full force. "Oh my God! Wait. Max, are you saying they ... I can't believe it." Her eyes widened in disbelief. "Do you know what this means? What are we going to do?"

"I have no idea," Max sighed. "We've got a powerless Michael and an empowered Maria. Sounds like your basic recipe for disaster."

Suddenly, an idea crossed Liz's mind. "Not necessarily." She started leafing through the pages of her biology textbook, frantically searching for a specific page. "Here it is: "In osmosis, liquid flows from the low solute side to the high solute side. However, this flow can be reversed by applying external pressure to the higher solute side. This is called reverse osmosis."

He nodded slowly. "So in other words, it's possible to transfer the liquid -- or in our case, power -- back to the source where it came from." Max frowned. "But power isn't a tangible medium, like water. It's an invisible form of energy. There's no guarantee this would even work."

"No," Liz agreed, "But if the power found its way into her body in the first place, then theoretically, there has to be some way for it to find its way back out. The question is, how?"

Max stared at her blankly. "Other than the obvious?"

"Other than that," she blushed slightly.

"That's the part I'm not sure of," Max admitted with a troubled look.

"Maybe Isabel might have an idea," Liz suggested.

"Isabel?"

"Yeah ... she sort-of knows about Maria," she shrugged. "She helped us conduct an experiment to determine the extent of Maria's powers -- that thing I was talking about, with the fork."

"She knows about Michael, too. She was there when his powers stopped working. And apparently, he's been practising with her to try and regain control over them," Max added, the conversation in the library with Michael making much more sense now, "But I don't think it's working."

Liz was pensive for a moment. "Scientifically speaking, we should probably try to prove our inital hypothesis before basing a subsequent theory on it."

Max frowned. "Meaning?"

"Meaning, we need to determine if your idea about ... osmosis ... is true, before we go any further. We have to figure out how the problem first came into existance before we can resolve it," she explained.

"I'll talk to Isabel tonight and see what we can come up with."

"I'll see if I can corner Maria," Liz said. Just then, the bell rang out. She stared at him in horror as a new thought flashed across her mind. "Oh my God, Max ... what if they didn't ... use anything?" Max looked at her uncomprehendingly, waiting for clarification. Her voice dropped to a whisper as students began trickling into the science lab. "What if they had ... osmosis ... without some sort of ... semi-permeable membrane?"

Suddenly, Max's face registered her words. "I-I .. I don't think ..."

Liz's voice began to rise again, in a panic. "What if this can't be reversed? I mean, what if she was ... What if these powers are some sort of hormonal pregnancy thing? Like the alien equivalent of morning sickness?"

Max was feeling a little sick himself at the mere thought of it. He swallowed. "Like you said ... Let's find out if our theory about osmosis is correct first, before we concern ourselves with the existance of any ... by-products."

"Good afternoon," Mr. Seligman called from the front of the class, abruptly putting an end to the conversation. "Please open your books to chapter 6 ..."

"Hey," Max greeted her, opening the door. "Am I interrupting?"

"Hey," she smiled. "No, I could use an interruption. This sine cosine stuff is making my head hurt. What's going on?"

"Not much," Max began, crossing over to her side of the room and leaning against her dresser. "I don't suppose you know anything about Michael's sudden loss of his powers."

It was a statement, not a question, and Isabel glanced at her brother uneasily. "Uh, no ... not really."

Max waited for her to elaborate, but she didn't. He sat down beside her on the bed. "So then, I don't suppose you know anything about Maria's sudden newfound powers, either?"

Her eyes widened in surprise. "How did you--"

"Liz told me."

Isabel nodded her confirmation slowly. "Maria just said she got inside Michael's mind one night, and the next thing you know, she's melting utensils and healing cuts." A note of alarm crept into her voice. "Did you tell Michael?"

"No. But he's going to have to find out sooner or later." Max stared at her, his eyes searching hers. "Do you have any idea how this happened?"

"No," she replied gravely. "Do you?"

"Liz and I were thinking Michael's powers could have flowed from his body into hers through some sort of energy transmission," he began. "Like--"

"Like sex?" Isabel interrupted, her nose wrinkling in disapproval.

"I was going to say like osmosis," Max corrected her. "But yes ... sex may have been a catalyst for it, or the medium of transmission."

"Ugh. Too much information, Max," she grimaced. "That's just a mental image I so don't want to think about."

"There's more," Max admitted.

"More? Do I want to hear this?"

"The thing is," he began smoothly, "As a result of all this, we thought Maria might turn out to be ..." Max stopped, trying to pick his words carefully.

"... Seriously delusional?" Isabel offered.

"Pregnant."

"What?"

He tried to explain, but it sounded ludicrous even to his own ears. "Liz thought that maybe the appearance of these powers in Maria could be a side-effect of carrying an alien fetus."

"This is rapidly disintegrating into a Weekly World News headline," Isabel muttered.

"The truth is, we don't know," Max tried to soothe her. "And until we know what caused this, we can't determine how to reverse it, or if it's even fixable. So I need you and Liz to talk to Maria, see if you can get her to admit to anything. I'll work on Michael."

"Wait, you want me to ask Maria about the intimate details of her sex life? With Michael? Have the neurotransmitters in your brain short-circuited?"

"Isabel," Max cautioned, giving her a scornful look.

"I'm just saying," she muttered. Her fingers reached out and twisted around the pendant she had taken from the geodesic dome, which now hung around her neck. Her brother eyed the necklace, his eyes narrowing. Isabel looked at him suspiciously. "What?"

"Maybe there's an easier way to do this," Max said, lost in thought.

"God, I sincerely hope so," Isabel replied dryly. "What did you have in mind?"

Max's gaze travelled from the pendant to his sister's face. "River Dog. He's helped us before -- Michael was even talking about going to see him about this whole thing earlier today. Maybe he might know what to do."

"Wait, now you're going to get River Dog to poke and prod into Michael and Maria's sex life?" Isabel was appalled. "That's even creepier than asking me do it."

He looked at her in exasperation. "Look. We need to fix this, and right now, nobody has any clue how to do that. Do you have a better idea?"

Isabel shrugged, and looked away, still disgusted with the idea of Maria and Michael being intimate. "Move over, Dr. Ruth," she muttered. "You've got competition."