Wrapping a towel around her, she stepped from the shower and carefully walked back to her locker. All she needed to do was slip on the wet tile when she was all alone. Yeah, that would be good. She could see the headlines now - "Girl, 16, Left Unattended in Locker Room, Dies from Head Injury." She laughed softly to herself and began pulling on her clothes.

A noise off to her right distracted her. She hoisted her jeans over her hips and zipped them as she walked in the direction of the noise. In the next row of lockers, Isabel was huddled on the floor, her knees pulled up to her chest. She appeared to have been crying. Liz approached her, keeping her distance - she'd seen what Isabel had done to Max. There was no way Liz could go to a mirror and fix a broken nose if Isabel decided to give her one.

"Isabel?" she said gently.

Isabel gasped in a breath, wiped her eyes with both hands, but didn't reply.

"Is?" Liz knelt down beside her.

Isabel stopped crying, but seemed to have trouble catching her breath. She turned wild brown eyes to Liz. "Max," she gasped.

"What, Isabel?"

A rush of blood suddenly poured from Isabel's nose. Liz shrieked, but had the sense to grab a nearby towel and put it over Isabel's face. The tears started to pour from her eyes again and she grabbed Liz's arm.

"Get Max!" she ordered, her voice muffled by her tears and the towel.

Liz scrambled to her feet, was thankful she'd remembered to put her shirt back on before rushing from the locker room.

Max was at his locker getting out books for his afternoon classes. He was tired - he hadn't gone back to sleep after retrieving Isabel from Michael's apartment. As he was pulling the last book from his locker, he was shocked to see Liz Parker suddenly standing beside him. For a moment, his world stopped - his stomach did a little flip and his heart started to beat a little faster. He hoped the smile he felt inside hadn't reached his lips - he'd been trying his damnedest to not let his feelings for Liz show. He didn't want to give her any false sense of hope. Wait - why was she wet? And barefoot?

"Come with me," was all she said.

The urgency in her voice and the look in her eyes compelled Max to toss all of his books back into his locker and follow her. She took him to the girls' locker room, and after making sure the coast was clear, led him inside to a row of lockers.

Isabel looked up at him, the towel now nearly saturated with her blood. Her eyes pleaded with him as he knelt beside her.

"Let me see," he said gently as he pulled the towel away. He tilted her head back, then waved his hand across her face. The bleeding stopped. "It's okay. It stopped."

Isabel sobbed, fell against his shoulder. "What's happening to me, Max?"

"I don't know. We'll find out." Without turning to face her, Max addressed Liz. "Liz, why don't you put on your shoes, get Isabel's things and meet us outside by the jeep?"

Liz moved to comply and Max helped Isabel to her feet.

In the jeep, Liz watched from the back seat as Max drove and Isabel stared absently out the side. Max had picked up one of her hands in his as he drove, and Liz was touched by his brotherly affection for his sister. Every now and then, he'd steal a glance at Isabel, a small frown creasing his features. Every now and then he'd steal a glance in his rear view mirror at Liz, hoping she hadn't noticed.

At the Evans' home, Max helped Isabel into her bed once again, stayed until she was sleep, then went back downstairs to Liz.

"Is she okay?" Liz asked, dropping the magazine she'd picked up.

Max slumped onto the couch, rubbing his eyes. "I don't know," he said wearily. "Something is so wrong and I don't know where to even begin."

Liz could see his frustration, but let him be the one to speak.

"I mean, it's not like we can just take her to the doctor and get a prescription or anything. Last night she was burning up, then she was fine. Good enough to go to school this morning. Then she starts bleeding buckets from her nose." He sighed in exasperation. "Not to mention what she did to me, and to Michael…"

Liz raised her eyebrows. "Michael? Did she hurt Michael too?"

Max realized he'd been babbling out loud, and that he'd let slip that something had happened with Michael. He eyed Liz cautiously, then decided that she'd held his most important secret for this long, she could hold another.

"Isabel went over to Michael's in the middle of the night last night," he started, unable to meet her gaze. "She…well, she tried to seduce him."

Liz's eyes were round. "That doesn't sound like Isabel."

"Tell me about it."

Liz got up from her chair and sat down beside Max. She put her hand on his leg - he could feel her warmth through his jeans and suddenly it was a little harder to think about Isabel.

"Let's think about this," Liz began, taking her hand away now that she had his attention and had given her invitation of comfort. "We know we can't take her to a doctor, but is there anything else we can do?"

Max noted that Liz was saying "we" instead of "you." He smiled to himself - she would always be there no matter what. "I, uh, gave her the alien exam last night," he said, embarrassed.

"Alien exam?" Liz bit her lip to keep herself from laughing.

"Yeah, I connected with her, checked her out." His checks reddened. "Not something you want people to know you did to your sister."

Liz let herself giggle. "You could make a fortune as a gynecologist - none of the embarrassing invasiveness. The women would be lining up at your door."

Max snorted softly.

"So, what did you find?" Liz quizzed.

"Nothing. Everything appeared to be okay."

Liz thought for a moment. "But what about infections?"

"Infections?"

"Yeah, you said she was running a high fever, then she was okay. Did you check for infection?"

Max shook his head. "I can't do that. All I can see is if things are working correctly, if molecular structure is sound."

Liz thought for a moment, then her face brightened. "Maybe you can't look for that, but I can!"

Max had a confusing vision of Liz connecting with Isabel. "What do you mean?"

She reached for Isabels' gym bag, rummaged around and pulled out the blood-soaked towel. "We've got all kinds of cells right here, Max. All we have to do is look at them!"

Max eyed the towel, got a sudden pain in his stomach. He hadn't thought to pick it up before leaving the locker room, but Liz had. She quite possibly had saved their lives - if anyone was suspicious of them and took a sample…

He smiled at her.

"Let's go to my place," Liz suggested. "I have some biology equipment there for a project I was working on."

"Okay, just let me check on Is first." ______________________________________________________________________

Jeff Parker was seated in the living room watching the news when Liz and Max arrived at the Parker's apartment. He looked at Liz, then motioned for her to stop before she retreated to her bedroom.

"Dad, you remember Max," she said as she sat down and Jeff hugged her.

"Of course. How's it going, Max?"

"Fine, sir."

Max watched as Jeff gave his daughter a loving kiss on the cheek before they parted. He was always touched by the affection Mr. Parker showed Liz. Then again, Max had always remained distant from his parents; if he had let them in, maybe he would get the same from them.

Liz smiled at Max and led him to her bedroom where she shut the door behind them and reached into her bag for the towel. She was already working the problem much to Max's amusement. She was so single-minded when it came to a scientific problem; tunnel vision had set in. He watched her scrape some of the dried blood from the towel onto a slide, then put it underneath the microscope. After brushing her hair out of the way and making a few adjustments, she sat back puzzled.

"What?" Max asked.

"Oh, nothing." She looked distant for a minute, then Max saw an idea cross her face. "It's just that your cells are so, well, different that it's hard to tell." She smiled at him and he gulped, wondering what her thought had been. "I need a constant."

"A constant?" He watched in horror as she started to slide on some plastic gloves and reach for a needle.

"Yeah. You know - you have to eliminate the variables. If I could -" her eyes settled on the bend of his elbow "- you know, get some cells we think are normal…"

Max put up a hand, his eyes never leaving the needle in her hand. "Wait, I understand what you're saying. But let me do it myself, okay?"

Liz hesitated, then smiled broadly. "Of course, do it yourself."

Max took a slide from her, then jabbed himself in the finger with the needle. She winced as he squeezed a dime-sized puddle of blood onto the slide; and just like that his finger healed shut. She took the slide from him, eyeing him curiously.

"Does it hurt when you do that?" she asked, slipping the slide under the microscope.

Max shook his head. "No. We're pretty good at blocking pain."

She looked up at him. "Yeah? Then why wouldn't you let me do it?"

His face reddened. He couldn't tell her that if he let her touch him he'd be so nervous he wouldn't have been able to block the pain. "It's just easier if we know when it's coming," he explained lamely.

"Uh huh." She returned to the slide, adjusting the focus. Wordlessly, she removed his slide, then put Isabel's back under the lens. "Wow."

"Wow? What wow?"

She reached for his arm, pulled him to the microscope as she slid his slide back under. "Look at your cells." She put Isabel's back into the microscope. "Now look at Isabel's."

Max drew in a breath. Compared to his cells, hers were smaller, darker in color

"It's like they're mutating," Liz speculated.