As long as I can remember, the Sowers house has been empty, just sitting there with its wood rot and its bats and the irreversible water damage happening to the grand piano that nobody ever bothered to move out of the parlor. There’s something spooky that happens with old empty houses, especially houses that are empty of people but still have all the furniture in them. I think that’s what brings ghosts. When you leave things the way they were, so that nothing changes in what they left behind.

Jim Pilcher said that when he was a kid, his uncle Steve put a twenty-dollar bill in the Sowers house, on this big old carved chest of drawers in one of the bedrooms upstairs, and said anybody could have it who would go into the house and get it, all alone at midnight.

“Did anybody ever get it?” I said.

“Not on your ever-loving life,” Jim said. “I gave it my best shot, thinking I could sure use a nice crisp twenty-dollar bill, and besides it would have been fun to shake it under my uncle Steve’s nose. So I went out to the house and I got the front door open, which freaked me out right there, because it squeaked and creaked something fierce, and then I got into the front hall — have you even been in the Sowers house front hall?”

“Yeah,” I said. “But not in the dark.”

“Well, it’s spooky as hell in the dark,” Jim said. “All these weird shadows and big black looming stuff that you can’t tell what it is. And then that hall chandelier — you remember that chandelier?”

“With all those glass prism things,” I said.

“So I’m just standing there in the front hall,” Jim said, “and all those little bits of prisms suddenly started shaking and shivering and clinking around, and I knew it wasn’t anything I’d done. It was like somebody was walking around right over it, upstairs. I didn’t like that one bit, but I took another step or two, because I still wanted to put one over on my uncle Steve. But then I heard what sounded like one of the stairs up above from the second floor creak — real loud, like somebody or something was stepping on it, coming down. And that was enough for me.”

“What did you do?” I said.

“What did I do?” Jim said. “I took off running, and believe me, you’ve never seen anybody run so fast outside of the Summer Olympics.”

Now, though, the house looked all lived in and warm, with yellow lights in the windows, and not the least full of ghosts. I figured any specter creaking around inside it would have been scared off by now by the twins. There were candles burning on the porch, the kind that are supposed to keep mosquitoes away but don’t very well, at least not around here, because our mosquitoes are too tough for citronella.

“You’re late,” Journey said.

The twins were sitting side by side on the porch steps, looking fairly human, so nobody had turned into a werewolf yet. Journey was wearing a yellow taffeta party dress and a pair of green rubber boots with frog faces on the toes. Jasper was wearing two left sneakers and a T-shirt that said I FIGHT ZOMBIES IN MY SPARE TIME.

“You know that you guys have a very unusual fashion sense?” I said.

“We were watching for you,” Jasper said. “But we didn’t see you because you’re wearing black like a spy.”

“If you were a captured spy,” Journey said, “would you rather be hanged by the neck until dead or shot by a firing squad?”

“Or sizzled up in the electric chair?” Jasper said.

“I’d rather not be captured,” I said.

“Shut up, twins,” Isabelle said. “Come on, Danny. Come up here and sit down.”

She was sitting in a wicker rocking chair and wearing one of those Indian-print skirts and a white top with skinny straps and silver earrings the size of hockey pucks. And she had those blue, blue eyes. Isabelle always took my breath away.

“You know Walter, don’t you?” Isabelle said.

And there on the other side of her was old weird Walter with his too-short pants and his chewed-up haircut, sitting on a little wicker stool so that his knees bent up practically to his ears.

It’s something you can’t explain exactly, why people become friends. It’s chemistry, is what they say. Maybe it’s just being the right people with the right feelings in the right place at the right time. But whatever it is, that summer Walter and Isabelle and I had it. And maybe even the twins too.

I wish I’d written down somewhere everything we talked about that night on Isabelle’s porch. At the time I thought I’d always remember, but then I didn’t, and now all that’s left of those conversations is a sort of flavor of something special and exciting and strange.

What I usually talked about with Peter Reilly and Mickey Roberts and Ryan Baker and all the rest was stuff like the Yankees and the Red Sox and the kind of motorcycle Peter was going to buy someday, when he had enough money to buy a motorcycle, and what really happened at the end of the Sopranos and who was dating who from school.

But with Walter and Isabelle and me, it was different. We talked about things that meant something. And we all listened to each other too, which, if you think about it, is rare. In most conversations, people don’t really listen. They just wait for you to be done talking and shut up so that they can say something of their own. Or they shut you up before you even begin, like my dad does.

All the time we were talking, the twins were running around in the grass chasing fireflies, which were blinking on and off all over the place like crazy things. Fireflies were new to them, due to there not being any in apartments in New York City.

“They’re magic,” Isabelle said. “They’re like little bits of stars.”

Then Walter, who sometimes can’t help himself, said that firefly light was really the result of an enzymatic reaction and that fireflies weren’t flies anyway, but beetles. I was worried that Isabelle would get upset with that, because even though Walter is a genius, his explanations can be real downers sometimes, but instead she just started to laugh.

“I’m not listening, darling,” Isabelle said, and she put her fingers in her ears.

It was right then on Isabelle’s porch, with the citronella candles with their fake-lemon smell and the creaking sound of rocking chairs, that I knew something was happening. That my life was beginning to change.

I knew that if at the lunch table at school, I told Peter and Mickey and Ryan and everybody that Walter was a really cool guy and we should have him come over and sit with us, they’d hoot and boo and laugh until milk came out of their noses and ask what I’d been smoking or if I’d been popping pills. They wouldn’t care that Walter knew all about parallel universes and philosophy and art and literature and beetles and all, because they wouldn’t see anything but that stupid haircut and that thing he does with his eyes.

I also knew if I took my tray over to sit with Walter, I might as well kiss my social life good-bye. Like my dad said, people judge you by your friends.

But something was changing all the same.

“Do you know how you can tell what a person’s truly like?” Isabelle said.

I said no and Walter said the Myers-Briggs Personality Test.

“No, darlings, it’s by their auras,” Isabelle said. “I learned to read them last year from this very spiritual woman, a holistic theologist, who teaches courses online. Your aura is the manifestation of your true nature. It’s why you see halos on angels and saints. Halos are really just very intense auras. On ordinary people, they’re smaller and paler.”

I could tell from Walter’s conflicted expression that he didn’t believe a word of this but didn’t want to contradict Isabelle.

“Come in the house for a minute and I’ll read yours,” Isabelle said. “You have to stand up against a plain white wall.”

The old Sowers house was really grand. The front hall had a marble floor laid out in squares, like a black-and-white checkerboard, and a huge curving staircase like something out of Gone With the Wind that went up to a landing with a big gold-framed mirror and then split into two staircases, one going right and the other left. Some of the spindles were broken out of the banister, and the red carpet was shabby, but you could still imagine what it must have been like at the old Sowers parties, with men in fancy suits with striped pants and women all glittering in diamonds and satin gowns.

Off to one side there was a little parlor, where Isabelle’s parents were sitting on a couch with the stuffing coming out, drinking something out of teacups and watching a news program on this very small television set. She introduced us and we all said hi. Isabelle’s father was more athletic looking than I would have expected from a professor, and Isabelle’s mother looked a little bit like Isabelle, but tireder, which was probably due to living with the twins.

Then Isabelle showed us the room where her father was writing his monograph, which had a big mahogany desk with a computer on it and piles of books and papers, and the room where her mother did her interpretive paintings. The paintings were propped up around the walls and were all in shades of purple and orange and looked like no cows that I’d ever seen.

“It’s a series. She’s calling it Atomic Moo,” Isabelle said. “She’s going to have a show next winter in New York.”

Which, though I did not say so to Isabelle, is the only place you could show cube-shaped orange cows without everybody laughing themselves sick. People in New York don’t know beans about cows.

Then she took us out to the kitchen, which had an old iron coal stove the size of a steam locomotive, with a new microwave perched on top of it, and then through to the butler’s pantry, which was mostly empty except for a couple of soup tureens big enough for baby baths.

“This is the only room in the house that has a plain white wall,” Isabelle said. “Stand over there. This will take a minute.”

So Walter and I stood against the plain white wall, and Isabelle took a few steps back, took a deep breath, and squinted at us.

She looked so beautiful standing there, and I thought that if Isabelle had an aura, it would probably be all silver and glowing like moonbeams and new snow.

She stared and stared until I started to fidget. Then she said, “There!”

“What?” I said.

“Yours is royal blue, Walter,” Isabelle said. “That means you have a strong balanced existence and you’re transmitting a lot of good energy.”

Walter said “Umf” in a noncommittal sort of way that managed to sound pleased and skeptical at the same time.

My aura wasn’t blue. It was yellowish brown.

“What does that mean?” I said.

“It means that your life is in difficulty,” Isabelle said. “Your psyche is suffused with pain and anger.”

Great, I thought. I felt like I’d flunked another math test. I could feel that aura hanging around me, full of bad energy and looking like old mustard.

Then the twins came busting in, yelling that we had to come out and see the moon, and so we all went back outside again.

And it was one fantastic full moon.

It was so bright that it made shadows on the grass. Everything looked all glazed with moonlight like sugar frosting, the trees and the bushes and the grass and the porch steps and the stone pillars at the end of the drive. And it was huge, like something out of a science-fiction movie. Like the moon the kid rode past on his bicycle in E.T. when the alien made everybody fly. It was so fantastic that I almost forgot I had an aura the color of baby poop.

“I think I’m turning into a werewolf,” Jasper said. “I feel itchy all over. I think I’m growing fur.”

“I think you’re not,” Isabelle said.

“And my eyes feel hot,” Jasper said. “My eyes feel really hot. Do my eyes look glowing and yellow? Like the eyes of a fierce wild animal?”

“No,” I said.

“I feel an urge to howl,” Jasper said.

“I feel an urge to howl too,” Journey said.

“I feel a need for silver bullets,” Isabelle said.

The twins started running around and howling, “AaaOOOOOO! AaaOOOOOO!” They sounded like wolf cubs who had maybe had their tails slammed in a door.

Isabelle said, “When I was little, I thought there were Moon Elves. I thought they’d fly down to earth on nights when the moon was full and perch on my windowsill. They had silver wings and silver hair and pearl-colored eyes, and they made little cheeping sounds like baby birds. I used to leave them things I thought they’d like to eat. Moon food. Necco wafers and dragées — you know, those little silver balls they use to decorate wedding cakes.”

We all looked at the moon.

I said, “When I was little, my mom showed me how to find the face of a man in the moon, but then Eli showed me how to find a rabbit, and after that all I could see was that rabbit.”

Walter said that there wasn’t any man or rabbit.

Walter has a very limited moon. All he sees are the Mare Imbrium, the Mare Tranquillitatis, the Oceanus Procellarum, and the Tycho ray crater.

Isabelle said, “Later I used to worry about the Moon Elves, that they’d gone away because I’d grown up. Like Wendy did in Peter Pan. I always thought that part was so sad, when Peter comes back for her, years later, and she’s too old to go back with him to Neverland.”

For a moment she looked sad, and then an instant later she was laughing again, and she threw up her arms and shouted, “Moon Elves! It’s me, Isabelle! Come back! Come back! I’m still here!”

And suddenly I remembered Eli. You know how memory sometimes comes in flashes, like a little video clip in your brain? Just a little piece of something, and you can’t remember what happened before or after, but the middle bit is really clear? I remembered sitting on the back porch steps with Eli and looking at the stars.

Clear nights where we are, it looks like there’s a million stars, though Walter, who has probably counted them and done a statistical analysis, says only six thousand are visible to the naked eye. But it sure seems like a lot more. There are so many, and they’re so far away, that it’s hard to look up at them without realizing that you’re really pretty incredibly small. Like Walter says, mathematically we’re nothing.

So Eli and I are sitting there, and there are peepers peeping — squee-squee-squee — like tiny little accordions, and fireflies blinking greeny yellow, and the Big Dipper dangling down over the barn, and I’m feeling small. Maybe Eli was too, because all of a sudden he jumped up and started to yell.

“Hey, universe! It’s me, Eli! I’m here!”

And he grabbed me and yanked me up.

“Come on, Danny! Make first contact!” he said.

So then we’re both yelling up at the sky, “I’m here! I’m here!”

Like the tiny little people in that Dr. Seuss book, Horton Hears a Who!

Suddenly I missed Eli so much that my stomach twisted up. I thought how I’d do anything to have him back again, even just for five minutes. Even for two.

“Danny?” Walter said. “Are you okay?”

“Yeah,” I said. “Sure.”

“Let’s dance!” Isabelle said.

She ran out into the grass and started spinning around and around on her bare feet in the moonlight, with her arms held out and her silky hair flying and her Indian skirt flaring around her knees, so that she looked like a twirling silvery flower.

So the twins stopped howling and started spinning too, and then so did I, and even geeky Walter, looking like a gawky human windmill, and then we were all spinning around and around together under that huge silver moon. To look at us, you’d think the moonlight had made us all crazy.

Walter says that in ancient times, people believed that moonlight did make you insane, which is why words like lunacy and lunatic come from luna, which is Latin for “moon.” You even got a lighter sentence for a crime if you committed it while there was a full moon. Which frankly gave me some ideas involving Mr. Engelmann, who teaches Algebra I.

In this case, though, it wasn’t just the moonlight. It was Isabelle.

Finally we got so dizzy with all the spinning that we just fell over in the grass, everybody laughing like zanies, and lay there, getting sopped by the dew and staring up at the spinning stars. I could hear the twins, who had fallen over on top of each other next to me, bickering about what stars would taste like if you could eat them, and Journey thought they’d be fizzy like ginger ale and Jasper thought they’d be tangy like lime sherbet, and then Journey said she thought she was going to throw up, but luckily she didn’t.

Isabelle reached out and touched my hand.

“Let’s always be like this,” Isabelle said. “Let’s be wild and free and young. Let’s believe in magic and wishing wells and fairy godmothers and love at first sight and doors in closets that take you into Narnia.”

“If Journey was in Narnia, she would be the White Witch,” Jasper said.

Isabelle wrapped her fingers around my hand and squeezed.

“Let’s promise that we’ll come back here to this very spot fifty years from now and we’ll dance in the moonlight again, all of us, because even when we’re old, we won’t have changed. Promise that we’ll never change.”

“Never,” I said. I would have promised her anything.

“Let’s always remember this night,” Isabelle said. “Let’s memorize everything about it so that we’ll never ever forget it and all the rest of our lives we’ll be able to close our eyes and it will come back to us just the way it was.”

So we lay there memorizing, which must have worked, because I can still remember how that night smelled of wet grass and roses and maybe a little whiff of pig manure, with the twins giggling and poking at each other, and Isabelle lying there, gleaming, with one arm behind her head, and Walter with his big bony knees bent up and his glasses white with moonlight.

The full moon always makes me think of Isabelle.

But at the same time I think about Li Po from my Book of the Dead. Li Po was an ancient Chinese poet who wrote more than a thousand poems, many of which involved heavy drinking. He was known as one of the Eight Immortals of the Wine Cup. One night, after a whole lot of wine cups, he drowned when he jumped into the Yangtze River, trying to embrace the reflection of the moon.

Thinking back, I guess that was what I was like with Isabelle, except without the cups of wine.

The truth is that everything always changes.

And some things you just can’t have.