"Aunt Cecelia, he's seven years old. I babysit for him."

My aunt was about to protest when Becca came home, as starving as I was. She also requested a sandwich and got two measly cookies instead. Since she ate hers, I ate mine after all. (Oh, I think I forgot to mention that the cookies weren't anything fun, like chocolate chip. They were oat-bran bars.) "Okay," I said, jumping up from the table. "Gotta go! I'll be at the Rodowskys' until a little after five. Then I'll be at Claudia Kishi's for our Baby-sitters Club meeting."

"Wait a minute," said Aunt Cecelia. "Where are you going?"

"To the Rodowskys' and then to Claudia's."

"I don't know those people."

"But I do."

"But I can't let you go running off to strange places."

"They aren't strange!"

"They are to me."

"Aunt Cecelia, you don't understand. This sitting job is my responsibility. I baby-sit all the time. You have to let me go."

"I don't have to let you do anything," said Aunt Dictator. "Besides, you are my responsibility now. I'm in charge while your parents are out. If anything happens to you, I'm - "

"I know. You're responsible," I said. "But I have a commitment. I told the Rodowskys a week ago that I would baby-sit this afternoon. They're counting on me. And a good baby-sitter never lets her clients down. Unless there's an emergency," I added.

Aunt Cecelia looked thoughtful.

"You can call Mama or Daddy at work and tell them what my plans are. They'll say I can go. This is my schedule. And these are my responsibilities."

"All right/' said Aunt Cecilia at last. "What time will you be home?"

"Ten after six. Baby-sitters Club meetings always end at six o'clock. Then I ride my bicycle home."

Aunt Cecelia nodded. "Very well, then."

I made a dash for the door - for two reasons. 1.1 was about to be late. 2.1 didn't want Aunt Dictator to change her mind.

I had to speed to the Rodowskys'. I was glad Aunt Cecelia couldn't see me. I didn't break any laws, but I nearly broke my head riding over a curb. I arrived at Jackie's house in one piece, though.

"Hi," I greeted Mrs. Rodowsky breathlessly. I glanced at my watch. "Boy, I just made it. I'm sorry I was almost late." (A good babysitter tries to get to any job, even the most routine one, a few minutes early in case the parents have special instructions, or there's a problem, such as a child who's going to cry a lot when Mommy leaves.) "Don't worry, Jessi," said Mrs. R. as she let me inside. "I know I can count on you."

I wish Aunt Cecelia would count on me, I thought.

A few minutes later, Mrs. R. left with Shea. Archie was supposed to have gone with her - to be dropped off at soccer practice - but he had stayed at home that day, recovering from an ear infection.

"He's on the mend, though," his mother had told me. "He'll be back in school tomorrow. He doesn't need to stay in bed, and don't worry about medicine. I'll give him his next dose at suppertime."

So I was left with Jackie and Archie.

"Okay," I said enthusiastically to Jackie. "Let's get to work on your volcano. Did your mom and dad buy the things you need?"

"Yup," replied Jackie.

He and Archie and I were in the Rodowskys' playroom. Archie looked at his big brother and me with interest. "Can I help?" he asked.

"This is Jackie's project," I told Archie.

"Oh. Can I watch, then?"

"Sure," I replied. I turned to Jackie. "Now the first thing we need to do is build that box, the gla.s.s one with the wood frame that we'll put our volcano in," I said.

"Our volcano?" asked Jackie.

"I mean yours. Now let's see. Where are the instructions?"

"You don't have to worry about that," said Jackie. "My dad and I made a box over the weekend. It doesn't look exactly like the one in the picture, but it's gla.s.s, and it's big enough for the volcano."

"Oh, good," I said. I felt relieved. Building the box had sounded difficult, even harder than making a working volcano. "Then we can get started on the next step," I told Jackie.

"Yea! Papier-mache!" he cried. (Just the idea of something messy is appealing to Jackie.) "Nope," I said, referring to the instructions. "First we have to build up the layers of igneous, metamorphic, and sedimentary rock. We'll use the Plasticine for that. Did you buy three different colors of Plasticine?"

"What's Plasticine?" asked Archie, who was beginning to look bored.

"Modeling clay," I told him. "Did you get some, Jackie?"

"Yup. We got red, yellow, and brown. But, Jessi, clay doesn't look like rocks." Jackie sounded worried.

"It doesn't matter," I told him. "It's supposed to represent rocks."

"Can't we just build a volcano?" he asked.

"Not if you want to win a prize in the fair. You have to do a really terrific project. Now where's the clay? And the box?"

Jackie set out the materials on an old table in the playroom. He watched while I built up the layers of rock that lie under volcanoes. It didn't take me too long.

"Goody!" he exclaimed as soon as I was done. "Papier-mache time!"

Before I knew it, Jackie was mixing flour and water, and Archie was tearing strips of newspaper. Apparently, they had made papier-mache before.

"Goop, goop, goop," sang Jackie, as he slurped his hands in and out of the pasty bowl. "Hey, this is a good batch, Archie," he said. Jackie was up to his elbows in goo. He grinned happily.

"Okay," I instructed, "take the papier-mache and build a mountain on top of the clay, and around this tin can. Don't fill the can in. That's where we'll put the chemicals to make the lava."

"Mmmm," said Jackie. He held up his hands and let the goop drip back into the bowl. Then he got an itch and wiped his cheek, leaving papier-mache smeared across it.

I tried to ignore that. I read up on igneous, metamorphic, and sedimentary rocks. But in the background, I was aware of cries of, "Got you! I'm the slime monster!" and, "Hey, Ar- chie, look. If you wrap the papier-mache around your arm you can make a cast/' and, "Cool. Wrap me all up, Jackie. Make me a mummy!"

I glanced at the boys. They were having the time of their lives. Papier-mache was everywhere - except surrounding the can in the gla.s.s TDOX. Jackie hadn't started his mountain yet.

"This is so, so fun!" he exclaimed, just as I was about to tell him to get to work. "I can't wait to see lava, lava everywhere!"

I looked at my watch. "Time to clean up, guys," I said. "Your mom and Shea will be home soon."

"You know what, Jessi?" Jackie replied. "This was the best afternoon of my life!"

Chapter 8.

Uh-oh. I should have known.

Compet.i.tion.

When Kristy gets involved in something, the compet.i.tion heats up right away. (I bet if you opened Webster's and looked up "compet.i.tion," you'd find a picture of Kristy's face.) Kristy now saw the science fair as a compet.i.tion among Mallory, herself, and me, as well as among all the kids in the fair. It would be like . . . well, like if David Michael won, Kristy would have won. In other words, she would have beaten me. At least that's what I thought at first. Things turned out quite differently.

Anyway, Kristy was baby-sitting that afternoon. Nannie had just driven off in her car, the Pink Clinker, and Kristy was trying to think of something fun to do with her little brother and sister. Usually, David Michael wants to play outside, but that afternoon he curled himself up in an armchair with his second-grade science book and began poring over it.

"What are you doing?" asked Kristy. (David Michael practically has to be bolted to his desk to do the small amount of homework he sometimes gets. He's smart, but he doesn't like school much, and he really doesn't like homework, particularly during softball season.) "Well," said David Michael, "see, there's going to be this science fair at school. Do you know what that is?"

Kristy hid a smile. Of course she knew what it was. She'd gone to Stoneybrook Elementary herself and had entered several of the fairs. But all she said was, "Yes."

"So I might enter it," said David Michael casually.

"Oh, yeah?" Kristy replied, just as casually.

"Yeah. There are prizes."

David Michael continued to flip through the book, while Kristy kept an eye on Emily, who was stacking blocks nearby.

"But," David Michael went on, "I'm not too good in science."

- "You could enter anyway," Kristy told him. "Science isn't my best subject, either, but it's fun to enter the fair. Is there anything about science that you like?"

"s.p.a.ce," said David Michael immediately. "Aliens. Flying saucers."

"Some people say that's science fiction," Kristy told him. "You know. Made-up stuff."

"Well, I still like to think about Mars and Pluto and all the planets. I like Saturn best, because of its rings."

"So do a project on the solar system," said Kristy.

"Make a list of all our planets?" suggested David Michael.

"No. Something a little more ambitious. Go out there and show what you can really do. Like when you're up at bat in a softball game. Think, 1 can do something big.' "

"I'll make a huge Saturn!" cried David Michael, inspired. "I'll use a beach ball, and I'll put hula hoops around it for rings."

"That's the spirit," said Kristy, "but it isn't science-y enough. You're going to be competing against some kids who are playing hardball."

"Huh?"

"Kids who really know science. Kids who will do great experiments. You've got to do something better than them if you want to win."

"Help me, Kristy," said her brother, plaintively.

Kristy paused. "I'll help you," she said at last, "but I won't do the project for you. Just like I can give you pointers on how to pitch a ball, but when you're on the pitcher's mound during a game, you've got to throw the ball, not me. Okay?"

"Okay." David Michael turned back to his book.

"Hey, Emily," Kristy said, "what are you building?"

Emily looked up from a messy tower she was working on. "Building," she repeated, smiling.

"You're building a building?"

Emily looked frustrated. "No!"

"What are you building?" Kristy repeated patiently.

"Bwocks."

Kristy sighed. Emily Mich.e.l.le is what the pediatrician calls "language delayed." And it's no wonder. The first part of her short life was spent in an orphanage in Vietnam, where she was spoken to in a foreign language (Vietnamese, of course), when she was spoken to at all. Then she was uprooted at the age of two and flown to a completely new country where she didn't understand a word anyone said to her. Believe it or not, Claudia has been working with Emily some afternoons, teaching her vocabulary and concepts and other things that most two-year-olds already know.

Emily looked frustrated with her block-building, so Kristy decided to give her something new to do.

"Hey, Emily," she said. She led her away from the blocks. "Show me your nose. Where is your nose?"

"Nose," said Emily, pointing to it proudly.

"Good girl!" cried Kristy. (Claudia said that Emily learned fastest when she was praised for her good work.) Then, without being asked, Emily pointed to her eye and said triumphantly, "Eye!"

"Great!" exclaimed Kristy. "Where's your ear?"

Emily pointed. "Ear."

"Oh! I just thought of a great song for you, Miss Emily," said Kristy suddenly. "Come over here. We need s.p.a.ce."

Kristy led Emily to the middle of the den, away from furniture. "Watch this," she said, and sang a song she'd learned in preschool.

Head, shoulders, knees and toes, knees and toes. Head, shoulders, knees and toes, knees and toes. Eyes and ears and nose and mouth and chin. Head, shoulders, knees and toes!

Kristy pointed to each body part as she sang the word. The song is fun, especially when you get going fast. (I can't wait until Squirt is old enough for it.) Emily had smiled while she watched Kristy.

Now Kristy took her sister's hands and placed them on her head and shoulders and so forth as she sang the song again. Emily laughed.

Kristy and her sister were going through the song for the fourth time when David Michael cried, "I've got it!"