When the dog dies, she doesn’t know she is dying. You shouldn’t feel sorry for her. To her, life lasts forever.
Infants and dogs recognize the flow of time, but not their presence in it. Psychologists show two films to a child so young it cannot comprehend the difference between itself and the universe. In the first film, water pours from a pitcher into a glass. In the second, time is reversed: water spirals out of the glass to replenish the pitcher. The child will stare longer at the film that violates the rules of causality. She believes, without knowing she believes, that time goes one way.
She doesn’t know that time pervades her very flesh, a dimension of her physical existence. She doesn’t know that it will require her to die. She believes that time is progress. For a while, you believe it, too, and the mistake damages all your equations. It isn’t until Jane dies that you reach the solution.
You don’t know it yet, but there is a feeling of being inside time. It suffuses your awareness as thoroughly as your height and weight and position in space. It is as comforting as riding at a constant speed and in a constant direction, rocking to sleep on a train or in a car driven by someone you trust. When you go back in time, it hurts.
The first injection calms the dog. Her breathing slows, and she puts her head on your foot. It is an unexpected move, and a little unsettling. Jane has seldom wavered in her determination to watch over you. She watched when you went to the bathroom. She followed you without condemnation when you walked up the stairs, forgot why you were there, and immediately descended with her in tow. She watched today as you made the last batch of muffins. She kept an eye on your movements even as she licked the bowl. For you, it’s the last time she will ever lick the bowl. For her, it’s forever.
The sedative allows her to relax in her self-appointed duties. Her watchfulness fades and she looks past you.
Jane doesn’t know about the drugs. She just transitions from what she was to what she becomes, as unaware of her own trajectory as she is its destination.
The second injection places her in a profound sleep. She’s unaware of anything happening to her, unable to feel pain. You touch her paws, stroke the black curve of her nails, but she does not withdraw.
“Don’t leave me,” you whisper, knowing the only reason you can ask is because she cannot understand. Her existence is a secret you can never tell her. If she ever learned, she would know she is dying.
The last injection stops her heart. It feels as if your heart stops, too, ceasing its stuttering progress through space.
You shouldn’t feel sorry for her. She lived forever.
When you first found her, Jane had a broken leg and a healing gash over the bony ridge of her pelvis. She had been hit by a car on New York Avenue at 4 a.m., and was picked up by the crew of a passing trash truck. It took two people to lift her into the cab for a trip to the emergency vet. She snapped weakly at their hands, furious at her pain.
The company fired the driver for diverting from his route. Sometimes you wonder what might have happened if that man had gone to the shelter and found her recovering in her bare metal cage. There are no alternate realities in which he took Jane home and she watched over him the way she watched over you. No timelines exist in which she settled beside him on the couch and watched him as he watched TV, in which she walked with him and watched everything for a chance to prove her love.
There’s only one timeline. If you go back far enough and wait, you eventually find yourself exactly where you started.
You will go back anyway.
You like to joke that a time machine is theoretically possible, but that the materials are in short supply. You must first construct a stable wormhole. This would require harnessing a daunting amount of energy and solving certain problems related to the production of exotic matter.
Assuming you can overcome this technological hurdle, you would then place one end of your wormhole on Earth—preferably in your lab, where no one can mess with it. Put the other end on a spaceship and accelerate it to near the speed of light. Relativistic effects will gradually induce time drift between the two openings. After one year at .9 times the speed of light, the end on your ship has traveled 1.294 years into the future, compared to the aperture that you left behind in your lab.
There are problems. You can only travel between the two ends of your fabricated wormhole. You will never travel back to observe World War II. Dinosaurs will never come roaring through your portal to wreak havoc on the modern world, scaly metaphors for fascism and the fall of an empire.
Also, you do not have a stable wormhole and no plausible means of creating it.
For a while, your theories make you a star in the field. A few awards fall into your lap, and you believe the words engraved in the bases.
Then the accolades slip away and are redirected into the careers of colleagues with more plausible equations. Your lab space is reassigned to the nanoengineering unit, which filed actionable patents while you imagined flying about with a wormhole.
Eventually, you wonder if only your dog still cares about you.
You abandon the time machine, encrypt your files, and drift between ideas. Jane watches and follows as you walk around the house in a bathrobe. She still limps a little, a physical recording of past trauma. She rolls on her back on the couch as you waste a few hours of your life on an old sitcom. She growls as you rub her belly. The deep menace in this sound sometimes frightens people who don’t know that this is how she speaks her love.
She watches over you.
Then she struggles to get up, limping more noticeably, sensing that you’re upset and wondering how she can protect you.
She brushes her gray muzzle against your face, watching you to know how she should feel. You pretend to be fine and call her a good girl. She is a good girl. Your misery comes from watching her body falter, from the inevitable progress toward a terrible decision, but she can’t know that.
You’re sitting on the kitchen floor next to her as she pushes her food bowl around the tiles. The fridge rises like a steel monolith at your back. It is a place for giants. You feel secure next to her on the cool floor. She bumps you with the food bowl and uses your weight to pin it down while she finishes her dinner. You pat her side, and she burps before lying down, slowly, against your hip. You’ve forgotten to make yourself dinner.
Then it’s the day when she dies, although she doesn’t know it.
No one watches over you now. You’re free to spend nights in the lab, catching fitful naps under a desk, wondering what previous resident stuck their chewed gum in a line of Morse Code under the rim. The gum is the record of passing time, the message that is the past.
Then you understand: no one moves through time. Time is merely a form of encryption, much like the files on your computer. The past is decoded; the future remains locked into a cypher. The present is merely a floating translation point between encoded and decoded information.
There is only one timeline, one message. You might want to change it—to save a planeload of doomed passengers or avert a war. But you’re free of the burden of that power. When you go back, you’re simply re-encrypting the timestring. Your equations show, with almost total confidence, that you won’t be able to change anything.
You’re going back for one reason—to see your dog again.
When you go back in time, it hurts more than you thought possible. The universe presses its weight against you. Exploding molecules are welded back together. Healed wounds are torn open before ceasing to exist. Disentangled particles fall back under each other’s painful influence.
Pages come in contact, stick and knit back together. Your memories are stripped from you and scrambled into code.
When you go back, you don’t know you’ve gone back. You roll back the clock and experience your life again for the first time. You’re yourself, just as you always were, and always will be forever. You’re like Jane. You have no memory of the future. You just exist.
You walk past rows of metal cages—dogs clamoring for attention or turning in tight circles or huddling with their backs to the door. None of them are the dog you’re looking for. You hear the deep resonance of her voice from two rows down. The shelter staff tells you that this dog is scheduled to be euthanized. No one has come to pick her up. She has tried to bite two handlers and has been labeled a threat. In honor of her unknown origins, they have named her Jane Dog. Her barks rise in amplitude, as if she’s trying to catch up with someone who is walking away.
When you pass her cage, she leaps up against the wire mesh, breathes in your face, and watches you. Her flank is shaved over a ragged wound and her front leg is splinted. The staff member warns you to be careful. Jane’s eyes are nearly level with yours, and in them is an unwavering sense of purpose.
You tell the staff all the right things. You understand that she is dangerous, that she will require time and training and patience and structure and socialization, and still may always be in some way broken. You leave the building tethered to each other.
In three years, you will watch the needle slide into the soft fur, and cry uncontrollably, and struggle to remember life without her. You’ll bury your face in the thick, sable neck and feel more adrift than anyone has ever been in time.
It hurts the same amount every time, although you never remember the re-encryptions from one to the next. You collapse eventualities like a tent being folded in on itself. You bend along your dimensions in bone-shearing re-combinations.
Every time you return to the past is the first time. You have no memory of how many times you’ve gone back to be with her.
She loves the woods. Every breath is a painting: ochre splatter patterns of squirrels flashed through with bright blue glimpses of every dog who has peed on the scabby trunk of rotten oak. Green swirls of skunk sift through the trees.
You are tethered together in the woods when a man runs around the bend in a trail, arms pumping, puffing with exertion. You startle. Jane feels the tremor through the leash, and you don’t have time to pull her in close to your leg before the man runs past. She lunges, wrenching your shoulder with unexpected fury. The man pitches away and falls into the dead leaves. You’re apologizing and stepping forward to help him up, but Jane is barking and pulling, and the man looks more terrified every time you step closer.
“Holy shit!” he yells. “Control your dog!”
The man’s fear has transformed into anger. He’s tugging at the leg of his shorts, and you see the fabric is ripped. You’re apologizing and asking if he’s all right. There is no blood, no wound. You part forever.
In two years, the needle slides in and she’s dead. She’s dead and you’re back again to where she’s gone, your past decoded and painfully plain.
Did she always lunge for the man?
The memory feels fresh as a wound. Before you went back, did you remember the torn cloth in the man’s hand, the angular wedge of exposed skin? Did Jane wrench your shoulder?
Perhaps it always happened this way. There is no denying the fact that you remember it. The other possibility is terrifying: that the timeline is softer and more subject to revision than you had theorized.
If you can alter the timestring, then maybe you can make things better. This is almost as terrifying a prospect as helplessness.
There’s no way of knowing for sure. The lunge is coded into the universe now, a fossil pressed into stone. Somewhere out there, a man remembers the day he nearly was attacked.
What you are doing here suddenly feels strange and dangerous as theft. You walk the house alone. When you do laundry, trying to pretend that everything is normal, the lint trap is clean of dog hair, and you cry into the warm clothes.
So, you go back again.
When you return, when the needle goes into the soft fur, she whines for a moment, her eyes going wide.
Did she always whine? Perhaps you just forgot it in the terror of those final moments with her. Or perhaps you’ve further damaged her.
There are techniques in cryptography that allow one party to demonstrate that a given piece of information is true, without actually revealing the information to another party. These protocols can be used to verify the authenticity of encryption keys without disclosing the key.
Your perceptions are the result of progressive encryption. The message flows only one direction along the gradient, but you can use knowledge protocols to verify one piece of information is true for the entire length of the information string.
You can’t retain your memories when you travel back, but you can broadcast one crucial piece of information to yourself. There is only one message that can be transmitted, and it is that this is not the first time the string has been decoded.
You’re watching television with Jane on the couch. Her paws are rough and warm. They smell like Fritos, although you have never eaten Fritos and subsequently found yourself thinking of dog paws. Some information flows only in a single direction.
The claws curve out of the soft fur over her pads. When you take a paw between your palms, she withdraws it, eyeing you for signs of intent to clip her nails. You take her paw again and rest it on your palm, and she watches with liquid brown eyes. Her front leg twitches, prepared to withdraw if the clippers appear.
“We’re holding paws,” you tell her.
There is something satisfying about annoying her just a little, seeing how much stupid behavior she’ll put up with. Sometimes, sitting on the kitchen floor together, you throw your arms around the sable ruff of her neck and hug her. She tolerates it for a moment because it’s you, and she knows you perform many meaningless actions. If someone else attempted this, she would probably bite their ear.
Then you remember, you’re time traveling.
You know nothing more of the future than this simple fact: this is not the first time you’ve lived this moment. At some point in your coming life, you will discover a way to return to this body on the couch with Jane, armed with the alarming piece of information that this is not the first time you’ve been here.
You look around the room. There’s an old episode of a sitcom on TV. Nothing here seems out of place. Why did you pick this moment? You wait, and nothing happens, except Jane rumbles a low growl and withdraws her leg. She stands up and moves further away on the couch. She’s had enough of holding paws.
In a year, you put your arm over her and bury your face against her neck. “Don’t leave me,” you whisper, knowing you could never ask this if she could understand. She whines when the needle goes in. You wait for another exasperated sigh, another breath. You put your hands over her soft, warm paws, caressing the rough pads, and she does not pull away.
Did she always growl on the couch when you held her paw?
Did she always lunge at the man?
Did she always whine when the needle went in?
Don’t leave me, you said. But you were the one who left her. She reached the end of her timeline and stopped, while you went on without her. Her life was completely decoded, but you are still living inside the cypher. You should not feel sorry for her.
What would have happened if you’d never loved Jane? You would never have been in the woods the day she showed you she would fight for you. You would never have thought her warm paws smelled like Fritos. You would never have sat together on the kitchen floor, with Jane snuggled against your hip, and realized you weren’t going to get up and make dinner if it meant leaving her.
What would happen if you went all the way back to before you ever met Jane in the shelter? What if the driver of the trash truck went into the shelter before you, and walked out tethered to her, and she went home with him, and watched him on the sofa and the kitchen floor, and endured his silly hugs and attempts to hold paws and show his love in all the strange ways you must when you know someone will die but can never speak it?
What would have happened if you were never driving along New York Avenue at 4 a.m. and felt a thud?
You hurt her. If there’s any way to go back and undo the hurt, you’re going to try it.
You go back. You are driving on New York Avenue at 4 a.m. and feel a thud. You don’t see anything in the rear-view mirror. A week later, you notice the dried blood on the bumper and go to the shelter, afraid of what you will find there.
She deserved better. She deserved never to meet you. You go back again.
You are driving on New York Avenue at 4 a.m. and you are time traveling. You don’t know how you’re aware of this, but at some point in the future, you will devise a means of returning to this moment. There is a thud.
Three years later the needle goes in, and you ask her never to leave you.
Jane deserved better than you. You go back.
You are time traveling as you drive on New York Avenue at 4 a.m. There is a thud.
A week later she rears up and breathes in your face in the shelter, and looks into your eyes, and you know that you would do anything to save her.
Three years later she is dying, and doesn’t know she’s dying. “Don’t leave me,” you whisper, knowing you can only say it because it’s in a code she cannot understand.
Then you are time traveling and wondering if in every iteration, you are harming her further because you can’t let go.
You are time traveling. There is a thud. Again, you feel the moment when you wrote the wound on her, inscribed the limp that lasted the rest of her life.
Still you go back.
There’s no way to know how many times you’ve been here. Each iteration feels like the first: a painful crushing-together of unfolded possibilities, the encryption of treasured memories into gibberish. With each reversal of time, the love you felt for Jane diminishes like a failing light until you’re in the shelter the moment before you saw her through the metal cage. Then it winks out entirely. The clocks move forward again, and it bursts into existence, the beginning of a new universe.
Always there is the thud, and always, three years later, the needle. And on this return—the first, or the thousandth—you understand that it’s not your first day that has drawn you back, but the last. Not the accident, but the needle.
You will go back one final time.
You find a way to fold one additional piece of information into the message you broadcast along the timestring: this is the last decryption.
You don’t go back to undo what you’ve done. You can’t hurt or love her any more than you already have. There’s comfort in that knowledge. You go back, just as you went back after the accident, to find her in the shelter.
You’re time traveling. You don’t know how you know, but at some point in the future, you will invent time travel, and you’ve returned to this moment for a reason. But this is the last time.
You are driving on New York Avenue at 4 a.m. and feel a thud.
A week later, you find dried blood on the bumper and you go to the shelter. The dogs clamor as you walk by the cages, but none of them are the one you’re looking for. You hear Jane barking as if she is trying to catch someone who is walking away.
This is the last time you will be here. It’s up to you to figure out why.
You stand outside her cage and she rears up to face you.
“Be careful,” says the man from the shelter.
Jane’s flank is shaved over a ragged wound and her front leg is splinted. Her brown eyes are calm and confident. She breathes in your face. You draw nearer.
Jane has been labeled as dangerous. She will need time and training and patience and love. You could fail her. She will never consider alternate timelines or wonder if she deserved better. She will never know when her last day comes.
This will be your only chance. The most important thing about this moment is not that it has never happened before, but that it will never happen again.
In three years, you will rest your hand in the soft ruff of her neck as the needle goes in, and she will relax under your hand, and you will let the moment go.
You touch her bandaged paw through the cage. She does not withdraw.
“I’ll never leave you,” you whisper, and you never do.