The pond only looks bottomless.

Clambering up the moss-slick stones beside the waterfall, finding purchase with cramping toes and fingers, if I chance a look back over my shoulder, the pond is a moonblack sky even on a sunny summer's day. It absorbs light. I push back off the narrow ledge, as hard as I can, always feet first, hoping I miss the rocks, hoping I don't overshoot the middle, hoping I won't lose my bathing suit on the way back up because Otis and Kat are here too, and I'd become a legend in all the wrong ways.

When I'm in the water, plunging, sinking, one hand dragging my sagging waistband back to something approximating my waist, wondering why I let Kat convince me to buy this suit in the first place, I let myself drop as deep as I possibly can. I trail my toes in the silt, and there is silt, and some kind of tough grass that wraps long fingers around my calves, and silt and grass mean there is a bottom. If I open my eyes, if I ignore the grit, I might catch a glimpse of trout silvering between the grasses. Or a water snake, black in the blackness.

That's all universal to everyone jumping, I think, except maybe the bit about the suit. And except maybe the next bit, where I come up gasping, and immediately go under again as Otis crashes in on top of me.

"Jerk!" I say when we've both surfaced. "One at a time! That's the rule!"

"They aren't rules, Shay," Kat says from the shore. She's spread a large towel over the flattest boulder, and she's sitting at the center reading a paperback with both covers missing. "They're superstitions."

"Easy for you to say, chicken." Otis skims his hand across the water, sending a plume her way that dies before it touches her. She doesn't even flinch. I make a mental note: cool is in not flinching. Cool is in keeping your resolve not to jump, even when your boyfriend calls you "chicken." If I have any cool at all, it comes from the fact that I jumped before either of them. I didn't even do it to impress them. No peer pressure here.

Anyway, Kat's not wrong. They are superstitions. Everyone in town follows them, except when they don't.

The rules:

1. One person at a time, so everyone can see if the pond is hungry.

2. No skinny-dipping, so your friends will know if you were taken or you just drowned. (Clothes don’t get taken.)

3. Don't jump if anyone depends on you.

4. Saying "one more jump" is just tempting fate.

5. Jump, don't dive. The pond prefers divers.

6. Don't jump alone.

Number three has variations. Some say it's more like "don't jump when you're in love." Others say the rule is "the pool can't take you if you're truly in love," in which case Otis is actually being romantic. That's what he claims. He loves Kat, and she loves him back. He always jumps anyway, just once, not usually on me. She's never jumped. When he gets out, she always slugs him in the arm before kissing him.

I'm maybe in love with both of them, or maybe just in love with the way they are around each other. I want to be the arm-puncher or the arm-punchee or the punch itself, or the plume of water that knows better than to drench Kat while she's holding a book. I want to believe they are superstitions, not rules, even though Kendra Butcher and Grant Pryor jumped together and vanished without a trace. I was there that day, though I wasn't ready to jump yet myself at the time.

The thing about the rules is they don't change anything at all. The pond doesn't follow any rules. They're just things people made up and passed down to make us feel better about our chances. To remind us what's at stake. Something to cling to when we're telling somebody's parents and they're nodding like of course, this is the risk we all take, and they shouldn't have jumped together.

People break the rules all the time. My brother Nick used to jump alone. When he disappeared, three years ago, his old Buick Century was found at the far end of the dirt lot where people park to hike down here if they come by car instead of by bike.

"Maybe he went hitchhiking," my mother said. "Maybe he'll be back."

Nick had done that before, too, going off for days without telling us where he was headed. But he hadn't tried to thumb a ride since he bought the car, and anyway nobody would hitchhike from that particular spot, since the only cars there were coming from or going back to our own town. It didn't make any sense for his car to be there unless he'd jumped.

We left the Century to sit unmoved. The spare key, the one that didn't disappear with Nick, lives in a bowl of coins near our front door. It used to be on top, but it gradually drowned in pennies and dimes. I know it's in there, but there's no use digging it out. I might have been able to drive the car away at the beginning, but I don't know where I'd have taken it. Since then, vines have grown over it and punched their way in through the windows. Somebody stole the hubcaps, and the tires have all gone flat and given in to rot. I think there's a raccoon living in the backseat. It's not Nick's anymore, not anybody's. Just a thing caught up in the slow process of transforming into another thing.

I can't say what happens when the pond takes a person. Only what we've all seen. Someone climbs the waterfall, pushes off the wall. The same way we all do. Same arc, same splash, but they never surface. There's no struggle, no roiling water, no sign anything was disturbed. A swimsuit will come floating up, which is why the old joke that the pond doesn't like synthetic fabrics. And we never see that friend/sibling/mother again. I've seen it happen twice with my own eyes. Kendra and Grant, both from my homeroom.

The bottom has been dredged at various points, once at my mother's request and my family's expense. People have gone in with scuba gear. They found a rubber boot, a bicycle, a picnic table. House keys and cell phones and car keys, though not Nick's. No bodies, no bones, no brothers.

There's always somebody who grew up here coming back to study it, only they realize quickly there's nothing to study. Set up a video camera and you could wait forever, and even if you caught someone as they disappeared, you've got nothing to show afterward. No proof it wasn't photographic trickery. No after to the before.

My father isn't one of the ones who came back to study it, but he's one of the few who came back. He says when he was a teenager, only boys jumped. The girls all sunned themselves on the flat boulder the way Kat does. Otis says he's heard the same; his mother's first and last jump was on her fortieth birthday. She and two friends drove out with a cooler full of pre-mixed margaritas to celebrate. I think that's why Otis prefers the "truly in love" version of the third rule, the version centered on romance, not responsibility. It used to bother him a lot that she took the chance, even if she did come back. He hasn't spoken about it since we started jumping.

My own mother isn't from here. She doesn't understand at all. She's the one who forced the town to put up a fence, so that now we have to climb over. She's the one who insisted Nick's car stay in the lot instead of taking it home for me. She closed the door on Nick's bedroom and left it untouched, just in case he comes back. Unlike the Buick, the bedroom has mostly stayed intact. Content the way it is, maybe, or on a slower journey.

I sneak in sometimes to go through Nick's stuff. I choose one area to explore each time, so if I find something I can pretend he meant me to find it at that very moment. The first fall he was gone, I discovered his copy of Twelfth Night right before my English midterm, with useful notes on every page. Another time, an issue of Penthouse, which cleared up some questions my parents weren't ready to answer and I hadn't yet worked up the nerve to research. Two years ago, I found a notebook filled with drawings of imaginary carnivorous plants. There was a folded page in the middle, and on it, in his block lettering:

Why We Jump

We jump because we have to.

We jump because we can.

We jump because we dare ourselves.

We jump because we're lonely.

We jump because we want to be alone.

We jump because once you're up there's really no other good way down.

We jump because otherwise we'll never do anything that matters.

We jump because we want to fly, just for a moment.

We jump because everything is better afterward: beer, breathing, sandwiches, sex.

We jump because the water is clear and deep.

We jump because there are so few things in life that can't be explained away.

We jump because we want to know what happens when the pond takes somebody.

We jump because we don't want that somebody to be us, or maybe we do.

We jump because otherwise we will never know who we are.

We jump because we want to know what else there is to be.

We jump because we don't want to be the kind of person who wouldn't.

We jump because each of us knows we are the invincible center of the world.

We jump because we want to be

We jump because

I can't tell if those last two lines are unfinished or how he meant them. I don't know if his "we" is meant to speak for everybody or just himself. I'm pretty sure I was meant to find this right when I did, right when the word "why" had started unmooring me. Nick's multiple becauses couldn't all be true, not all the time, but I liked the fact they couldn't be pinned down. They weren't answers. They were anchors.

I made my first jump the week after I found the note, dragging my friends along so I wouldn't chicken out. Just one jump, I promised. I didn't say: I want to do something that matters. I want everything to be better afterward, beer and breathing and sandwiches even if sex is not on the menu yet.

I can't say everything was better afterward, but I learned on the first jump that fear and relief are two forms of the same compound, like ice and water. The terror that built in my muscles and bones as I climbed the waterfall, as I pushed off, as I let go, it all bubbled out when I came up for air.

"What are you laughing at?" Kat called to me.

I just laughed and laughed, treading water. When we came back the next week, Otis jumped for the first time. Since then we've come out here at least once a week if the weather is at all conducive. It's not a decision on anyone's part. It's what we do. I'm happy to be part of this small "we" as well as the larger "we" that I think my brother was talking about, the "we" of everyone who has ever jumped or considered jumping.

I've added a few of my own ideas to my brother's list, speaking only for myself. I jump because I don't understand. I jump because something that is impossible shouldn't also be something that is true. I jump because Ms. Remlinger taught us about conservation of mass and conservation of energy, and a brother is not something that can become nothing.

Some people say when somebody's taken they're spit out somewhere else, clean and naked and ready to live a different life. Some people think they're reborn as babies, elsewhere. I don't find either idea all that appealing.

I don't imagine the people who are taken die or are reborn. I think they're transformed, but I don't know into what. Rainbow trout, black snake, water molecules. Is that different than dying? To become part of this beautiful pond, to receive the waterfall, to be surrounded always by rock and pine and birch and sky? A quick change. Quicker than my brother's room turning to dust, or the Buick becoming forest. People can change much faster than things can, if they're given the chance.

"Are you done?" Otis calls to me. He's standing over Kat, dripping on her. She scoots away with mock annoyance.

"One more jump," I say.

They both give me a look. I return my bravest grin.

I say "I love you" as I jackknife, not loud enough for either of them to hear me. Break the glassy surface. I'm not a fish or a snake or a baby on the other side of the world. The sky is impossibly blue, and the water is impossibly black. There have never been any rules.