Nancy was glad that he'd remembered to use her alias. The fewer people who knew her true ident.i.ty, the better.

"Hi, Nancy," the woman said. "I'm Phyllis Hathaway. Come into my office. I'll tell you a little about the program, then we can go down to check out the cla.s.sroom where you'll be working. Have you done much of this sort of work before?"

Walter rushed to answer before Nancy could reply. "Nancy has excellent qualifications," he said, his voice harsh and impatient.

Phyllis's expression hardened. "I'm sure she does," she said in a clipped tone that clearly said, Mind your own business.

The headmaster's face reddened, but he didn't say anything more. Instead, after another awkward pause, he said, "Well, I'll leave you to it. Nancy, if you need anything, just let me know."

He disappeared into his office, and Nancy followed Phyllis into hers.

"I hope that didn't make you uncomfortable," the woman said apologetically after they were seated. "I've been at Brewster for a number of years, ever since I finished college out in California. But Mr. Friedbinder is new to the place. We're still learning to work with each other. I guess we're experiencing what's called a personality conflict."

"That happens, I suppose," Nancy murmured. She glanced around the office. Half of Phyllis's desk was taken up by the high-powered computer work station Nancy had glimpsed before. The bookcase behind Phyllis's chair seemed to be filled mostly with software manuals and books on computer programming.

"I've heard that the school has a very advanced computer system," Nancy remarked.

Phyllis beamed. "It certainly does-the most powerful of any high school in the state. We're very proud of it, and I'm especially proud because I was able to help design it. I'm sure you'll enjoy using the system, too, once you get the hang of it. Now, here's what we hope to accomplish with the new tutoring program...."

As Phyllis spoke, Nancy realized that this case was going to be a challenge in more ways than one. In addition to unmasking the grade-changer, she was going to have to help students with their English, history, and social sciences. It sounded as if she was going to have to do a lot of homework herself!

"That's the plan in a nutsh.e.l.l," Phyllis concluded. "Now, why don't I give you a quick tour of the place?"

They were getting to their feet when the telephone rang. "Excuse me a moment," Phyllis said, reaching for the receiver.

Nancy stepped just outside Phyllis's office and waited. She was reading her notes and thinking over her approach to the investigation, when suddenly a phrase caught her attention.

"-too dangerous," Phyllis was telling the caller. "Listen, Dana, I don't like him any more than you do. I'd love to see the conceited nitwit squirm, but I'm not sure I want to go any further with this. Yes... okay... maybe I am am getting cold feet. But this could really hurt Brewster. I know... I know... the financial rewards are compelling. And I really do need the money. Let's just take it more slowly. This plan has the potential to end in disaster." getting cold feet. But this could really hurt Brewster. I know... I know... the financial rewards are compelling. And I really do need the money. Let's just take it more slowly. This plan has the potential to end in disaster."

Chapter Four.

NANCY EDGED AWAY from the office door. She didn't want Phyllis to guess that she'd overheard any of her conversation.

It looked as if Nancy had another suspect. Phyllis had a motive-apparently she needed money, though Nancy didn't know why. And who was it she wanted to see squirm? Maybe Friedbinder, considering their strained relationship. A grade-changing scam would accomplish both things. Phyllis had the opportunity, too. Who would have better access to the school's computer than she?

There was only one catch. Phyllis was tall and elegant. Even in a disguise she wouldn't fit the description of the pet.i.te I. Wynn-or of the woman who'd been seen at I. Wynn's Sycamore Avenue address. But maybe that was where this Dana person came in.

"Sorry to keep you waiting," Phyllis said, coming out into the anteroom. "Now let me show you the learning lab."

Nancy and Phyllis took the stairs up to the second floor. Using a key, Phyllis unlocked the door and ushered Nancy into a small room with a teacher's desk, four student desks, and a folding table that held a telephone, computer terminal, and a small printer.

"Once in a while you may have to share this room with Mickey Randolph-he's the other tutor," Phyllis told Nancy. "His specialty is science and math. Unfortunately he's out of town for the next few days, though. A relative pa.s.sed away."

"I'm sorry to hear that," Nancy said. In more ways than one, she added to herself. Randolph might have information that would help her.

"Yes, well, here is some background on each of your students," Phyllis continued, handing Nancy a manila folder she took from the teacher's desk. A schedule was taped to the top of the folder. "Let me give you a pa.s.sword so that you can use the computer, too."

Phyllis found a sc.r.a.p of paper on a desk and wrote out a code.

"NS four forty-four," Nancy read when Phyllis handed her the paper. "What does that stand for?"

"Nancy Stevens, four hundred and forty-fourth pa.s.sword," replied Phyllis. "I'll load it into the system when I get back to my office. You'll be able to use it right away."

"Thanks," said Nancy as Phyllis left. She sat back down in a student's seat and thought. Sally Lane's message had been sent by IW443. Four forty-three was the last pa.s.sword entered into the system before Nancy's. That could mean that the grade-changer was someone who hadn't been at the school a long time. Or it might mean that the person had two pa.s.swords and had a.s.signed himself or herself the I. Wynn pa.s.sword without the school's knowledge.

Yet Phyllis was aware of the number of the last a.s.signed pa.s.sword. It must be in her records. Did she know who was using it? Was Phyllis, herself, using it?

Nancy's thoughts were interrupted when her first student arrived. He was a tall, awkward boy named Dan. "I don't see why we have to learn this stuff," Dan mumbled as Nancy opened the history book. "These geeks are dead, man."

Nancy could see that she had her work cut out for her.

Her next two students weren't much easier. One was a girl with short red hair who needed help in English. Apparently, she had never bothered learning much spelling or grammar because she had Spellcheck and Grammarcheck on her home computer.

The other one was a girl who was failing history. She admitted to Nancy that she'd been caught writing her reports from miniseries on TV.

To each of the three students, Nancy asked the same leading question: "Wouldn't it be great if you could somehow change your old grades now that you're going to start doing better?" She asked it casually, with a smile, but her blue eyes scrutinized their faces for any trace of reaction. All three students agreed it would be wonderful, but Nancy didn't note any signs of guilt or nervousness.

Nancy glanced at the name of her fourth and final student before lunch. Victor Paredes. He was the guy Sally had named as the computer whiz, she recalled. Apparently he needed tutoring in English.

There was a tap on the open door. Nancy looked up and saw a guy standing there, grinning at her. He was very good-looking, tall and broad shouldered, with light brown, almost amber eyes, and dark brown hair.

"Hi, Teach," he said.

"Hi, Stu," she retorted. "Come on in."

Nancy looked over the sheet that detailed what he was supposed to work on, then got down to it. Victor was very quick, but it was obvious he had never bothered to spend more than two minutes on English grammar before. Now that he was was bothering, he caught on easily. bothering, he caught on easily.

"If any of my teachers were as pretty as you, maybe I would have paid more attention to this stuff," said Victor, gazing into Nancy's eyes.

"With lines like that I'm surprised you didn't didn't get better grades." Nancy laughed, trying to deflect his flirtation. get better grades." Nancy laughed, trying to deflect his flirtation.

At the end of one of the exercises, Nancy said, "Now, that wasn't hard, was it? It's too bad you can't go back and change last year's grade in English, now that you know how to do the work."

"Who says you can't?" Victor replied. "I could, if I wanted to."

Nancy started, then caught herself and said lightly, "Don't be ridiculous. Your grades are in your permanent file."

"Sure," said Victor, flashing her a dazzling grin. "And my permanent file is in the school computer, along with everybody else's."

Nancy fought to keep cool as she said, "Yes, I know. But you need special access codes to get to them, don't you? Otherwise, people would go around giving themselves whatever grades they wanted." She held her breath and waited to hear what he would say.

"There are ways to access those codes," Victor replied. "You'd have to be really smart to figure out how. But I could."

Nancy laughed. "You're not big on modesty, are you?"

Pink spots bloomed on Victor's cheeks. "Well, I don't want you thinking I'm dumb just because I bombed out in English," he told her. "I mean, being smart is sort of attractive, isn't it? And I want you to see my good side."

Again, Nancy tried to ignore his flirting, though she couldn't help being charmed by it a little, too. "You mean, you've figured out how to get into the locked files in the school computer?" she asked, trying to get the conversation back on track. "That's pretty amazing-if it's true."

"It's true, all right. Here, I'll prove it to you." He went over to the terminal and turned it on. "Let's see, what would light a fire under the honchos in the big office? Hey, I know!"

Nancy looked over his shoulder. His fingers were moving over the keyboard too quickly for her to follow, but on the screen she saw a demand for a pa.s.sword, then a directory of files. Apparently, Victor had somehow figured out how to get past the security codes and break into the system. The glowing cursor moved down the list of files and stopped at one named HEADMAST.BIO.

Victor pressed a couple of keys. The screen cleared, then filled up with Walter Friedbinder's biography.

"Now, what should we do with him?" Victor started typing again. Every now and then he gave a little snort of amus.e.m.e.nt. Finally, he turned on the printer, printed out the doc.u.ment, and handed it to Nancy. She started reading.

Walter "Twinkletoes" Friedbinder, the new headmaster of Brewster Academy, has one of the largest collections of soda bottle caps in the United States. He has earned degrees in both Fahrenheit and Celsius and is a founding member of River Heights's Flat Earth Society. Dr. Friedbinder's research into loose-leaf notebooks and the effects of heating them in oil led to his famous discovery of the fried-binder....

Nancy laughed. "Victor, what have you done?" she cried, trying unsuccessfully to scold him. "This is terrible!"

He pretended to be hurt. "I thought it was pretty good for the spur of the moment."

"But-but what if somebody sent this out, without noticing the changes you made? Mr. Friedbinder would probably fire them!"

"No problem, Nancy." Turning to the keyboard, he entered a couple of commands. "There, I've restored the original version. I'll show you."

The printer began chattering again. When it stopped, Victor ripped off the page and handed it to Nancy. Scanning it quickly, she saw it was a straightforward, unaltered press release about Walter Friedbinder. She folded the two pages and put them in her shoulder bag.

"Very impressive. Can you really get into any file in the school computer?" she asked. "Even stuff like student records?"

"Just about," Victor boasted. "Figuring out the access codes is my hobby, the same way some guys customize cars, or play video games, or collect weird road signs."

Nancy shook her head. "Aren't you running a big risk, though? Changing people's grades is really asking for trouble."

"Wait a minute," he said, holding up a hand. "I never said I was was changing grades, just that it wouldn't be that hard to do." He pointed toward the file folder on the desk. "If I was into changing grades, do you think I'd still have that D from last year's English cla.s.s on my record?" changing grades, just that it wouldn't be that hard to do." He pointed toward the file folder on the desk. "If I was into changing grades, do you think I'd still have that D from last year's English cla.s.s on my record?"

"That's a point," Nancy conceded. She was about to ask Victor more questions, but the bell in the hallway started to ring.

"Wow! I can't believe it's lunchtime already." Victor turned off the terminal and gathered his books. At the door, he looked back. "Thanks for the English lesson," he said. "I actually understood some of it. Hey, could I interest you in getting a burger after school? With me, I mean. My treat."

Nancy thought quickly. Victor might well be behind the grade-changing scheme. Even if he wasn't, he seemed to know more about the computer system than anyone else around. "Okay."

"All right! I'll meet you in the parking lot around three." He flashed her a quick grin, and then he was gone.

Nancy found herself smiling. She couldn't help liking Victor, so far. In the past she'd learned the hard way that-well, even bad guys could have charming smiles.

All the students were probably down in the lunchroom by now. This would be a good time to check out some of the other cla.s.srooms.

Nancy shut the door to the learning lab behind her. Checking each cla.s.sroom, she made her way down the second-floor hallway.

Half the school was on the first lunch shift, so many of the cla.s.srooms were empty. Nancy was looking for rooms with computers, places where the mysterious E-mail message might have been sent from, and also a place where the hacker-if it turned out to be a student-could sit, undisturbed, to work his or her grade changes.

Suddenly she stopped. Alone in a cla.s.sroom with three computers was a short, pet.i.te girl with shoulder-length dark hair held back with a headband. She sat working on one of the computers. When Nancy's shoe scuffed the floor, the girl jumped and turned around anxiously.

"Oh! You scared me!" she cried, seeing Nancy in the doorway. The girl wore an oversize purple sweatshirt over loose-fitting corduroy pants. Her surprised expression quickly changed to one of annoyance as she asked, "Are you looking for something?"

"Just checking out the building," Nancy told her. She introduced herself as Nancy Stevens and explained that she was the new tutor at Brewster. As Nancy spoke, the girl hit a few computer b.u.t.tons and closed out the file she'd been working on. Was she finished, Nancy wondered, or was she hiding what she had been writing?

"Catching up on homework?" Nancy asked pleasantly.

"Not quite," the girl said curtly. "My name's Randi Peters. I'm the editor of the Academician Academician." She was clearly impressed with her t.i.tle. "I'm working on an article for the paper. Hey, how about being interviewed?"

Nancy blinked. Had her cover been blown already? "Interview me?" she said cautiously. "About what?"

"About the tutoring program, of course," Randi said. "I haven't done a story on it yet. I think it's a natural, don't you?"

"Sure," Nancy agreed quickly. It was perfect-only Nancy hoped she she would be the one getting useful information. "But I don't have my schedule on me. I don't know when I'll be free. I'll have to call you." would be the one getting useful information. "But I don't have my schedule on me. I don't know when I'll be free. I'll have to call you."

Randi smiled. "Okay. See you soon, then."

Nancy said goodbye and returned to the learning lab for her afternoon tutorials. After her last student, she met Victor in the parking lot and followed his battered old green sedan to the Roost, a hangout a few blocks from Brewster Academy.

The place was just beginning to fill up. Nancy nodded to Sally Lane, who was sitting with friends in a nearby booth. With a quick tilt of her chin, Sally quietly acknowledged the greeting. Nancy looked around, admiring the dozens of high-school pennants hanging from the ceiling and the motorcycle fixed high on the back wall.

"There's a table over there," Victor said, pointing to the far side of the room.

"Great," said Nancy. "I'll just wash my hands and be right back."

As Nancy pa.s.sed Sally's booth, one of the girls sitting with her-she had short, wavy blond hair and pale blue eyes-looked up. Nancy was surprised when she saw the expression of hatred on the girl's face. She tried to think if she had crossed paths with the girl somewhere, but nothing came to her.

Nancy was drying her hands when the bathroom door flew open. Startled, Nancy glanced over her shoulder. The girl from Sally's booth was standing with her back against the door and her hands in the pockets of her leather motorcycle jacket. Her expression was even more hostile than before. There was no mistaking it now-Nancy was definitely the target of her anger.

The girl was short and delicate, but the fury on her face made Nancy cautious. She knew that rage often made people stronger than they seemed.

"I know who you are and what you're up to," the girl snarled.

Who was this girl? What did did she know? Right now the most important thing was to get away from her. "If you'll please move, I'd like to leave," said Nancy, advancing toward the door. she know? Right now the most important thing was to get away from her. "If you'll please move, I'd like to leave," said Nancy, advancing toward the door.

With shocking strength, the girl pushed Nancy back. "You're not going anywhere," she said in a voice full of menace. "Not until I'm through with you."

Chapter Five.