The Hermit said the Orbit of Weight was the first one most people learned and the last one they mastered. It was gravity's native language—the ability to alter your own mass, to make yourself heavier or lighter, to shift the relationship between your body and the planet beneath you. Simple in theory. In practice, it was the difference between humming a tune and conducting an orchestra.
Cael had been working with Weight since the first day of training. It was his oldest orbit—the one the OA had registered when he was six, the one they'd classified as sub-functional, the one that had let him lift a mop with slightly less effort than a normal person. He thought he understood it.
He was wrong.
"Light," the Hermit said.
Cael exhaled and let his mass drop. The sensation was familiar now but never comfortable—a feeling like his organs were floating inside him, like his bones had been replaced with something hollow, like his skin was the only thing keeping him from drifting away. His feet remained on the floor, but the floor no longer believed in them. He was a suggestion rather than a statement.
He jumped.
The bunker's ceiling was four metres high. Cael cleared it. His head punched through corroded metal—a sound like tearing fabric, like the building groaning in protest—and he found himself waist-deep in the floor of the level above, staring at a startled rat that regarded him with the offended dignity of a creature whose territory had been violated by an idiot.
The rat squeaked. It was a small, indignant sound, muffled by the dust and debris.
"Too light," the Hermit observed from below.
Cael pulled himself back down, showering rust and fragments of corroded metal. The rat, wisely, fled. Lyra, sitting cross-legged on a crate by the wall, was laughing so hard she'd folded in half, her arms wrapped around her stomach, her face red.
"Again," the Hermit said. "Half the reduction."
Cael adjusted. His Weight orbit responded, the gravitational flow smoothing into a gentler curve. He felt the difference—less float, more control. His feet still touched the floor, but lightly, like a dancer's, like someone who could choose to stay or leave at any moment.
He jumped.
This time he reached the ceiling and came back down cleanly, landing on the balls of his feet with a sound like a dropped pillow. The impact was soft, controlled, the force of his descent absorbed by his Weight orbit's careful calibration.
"Better."
---
"Now heavy."
The transition was harder than it sounded. Going from light to heavy meant reversing the flow of gravitational energy through his Core—like trying to breathe in and out simultaneously, like trying to laugh and cry at the same time. Most Orbiters needed a pause between states, a beat to reset, a moment to let the gravitational field stabilise before reversing its polarity.
The Hermit didn't believe in pauses.
Cael increased his mass. The floor groaned—a deep, structural sound that vibrated through his boots and up his legs. His boots sank half an inch into the concrete, which cratered beneath him in a circle of compression fractures, the stone pulverised by the sudden increase in weight.
He felt the mass in his knees, the joints compressing under the load. In his spine, the vertebrae settling closer together. In his jaw, the muscles tensing against the effort of holding his head upright. His heart had to work harder to pump blood that suddenly weighed three times what it should, and he could feel each beat as a hammer strike against his ribs.
"How heavy?" the Hermit asked.
"Three hundred kilos. Maybe three-fifty."
"Go to five hundred."
Cael pushed.
The floor cracked. Not just the surface—the structural layer beneath it, the reinforced foundation of a bunker designed to survive orbital bombardment. The sound was a sharp, percussive pop, followed by the grinding of stone against stone as the concrete settled into its new configuration.
He heard bolts shearing somewhere below—metal screaming, then falling silent. His vision greyed at the edges as blood pressure struggled to reach his brain, and for a moment he felt the familiar tug of unconsciousness, the warm pull of nothing.
"Enough." The Hermit's voice cut through the strain. "Come back."
Cael released the weight.
The rebound was worse than the compression—a moment of nauseating lightness, like falling up, like the floor had suddenly dropped away and left him floating in a void. His mass stabilised at its natural level with a jerk that made his teeth click together. He staggered, caught himself on the wall, and stood there breathing hard while the bunker settled around him with metallic creaks of protest.
---
"You're brute-forcing it," the Hermit said. His voice was calm, clinical, but there was an edge underneath—the edge of someone who had seen this mistake before, made this mistake before, and was trying to prevent someone else from repeating it. "The transition is too sudden. You're slamming doors instead of opening them. Weight isn't about making yourself heavy or light—it's about persuading gravity to change its mind about you."
"Gravity doesn't have a mind."
"Everything has a mind, boy." The Hermit's pale eyes were very serious. "Everything has preferences. Gravity prefers mass. It likes things that are heavy, that stay where they're put, that don't float away. Your job is to negotiate—to offer it more or less of yourself and make it think the change was its idea."
Cael wiped sweat from his eyes. His hand came away wet, and his uniform was soaked through, clinging to his skin. "You want me to flirt with gravity?"
Lyra snorted—a sharp, surprised sound that she tried to cover with her hand. The Hermit ignored them both.
"Again. But this time, transition smoothly. Light to heavy to light in a single breath. No pauses. No spikes. A wave, not a cliff."
Cael closed his eyes.
He felt for his Weight orbit. It was there—a slow, steady rotation around his Core, one of the original four he'd lived with his whole life. But it had changed since the training began. What had been a dim ember was now a steady flame, responding to his will with an immediacy that still surprised him. It pulsed in time with his heartbeat, warm and familiar, like a second pulse beneath his skin.
He began the transition.
Light. He let his mass decrease gradually, like a held breath slowly released, like a door opening on quiet hinges. The floor's grip on his feet loosened. His body rose onto his toes. The air felt thicker, more supportive, as if the atmosphere itself was conspiring to hold him up. He could feel the individual molecules pressing against his skin, offering their resistance, their acceptance.
Then, without stopping, he reversed direction.
Light to heavy in a continuous curve, mass increasing like a tide coming in, like the slow, inexorable pull of a moon on an ocean. He felt gravity reach for him—not grabbing, not demanding, but welcoming. Pulling him down with the patient insistence of deep water, of something that had all the time in the world and was willing to wait.
His feet pressed into the floor. The concrete accepted his weight without cracking this time because the increase was gradual, distributed, negotiated. He could feel the stone's structure—the way it was designed to bear load, the way it had been reinforced after the Fall, the way it had settled into its current configuration over decades of use.
At the peak of heaviness—four hundred kilos, he estimated—he reversed again.
Heavy to light, the mass bleeding away like heat from cooling metal, smooth and inevitable and controlled. His body lifted onto his toes again, lighter than before, lighter than seemed possible, and for a moment he felt like he could drift upward, through the ceiling, through the city, through the sky itself.
He opened his eyes. The Hermit was watching with an expression Cael had learned to recognise: clinical assessment layered over something that might have been pride.
"Better?"
"Better," the Hermit confirmed. "Now do it while moving."
---
What followed was three hours of controlled chaos.
Cael ran laps around the bunker, shifting his weight with each stride—light on the push-off, heavy on the landing, using his mass as a pendulum to generate speed that no amount of muscle could match. His feet struck the floor in a rhythm that was almost musical, each impact a note in a composition he was writing in real time.
He leaped from wall to wall, making himself feather-light at the jump and stone-heavy at the impact, driving his feet into concrete with enough force to anchor himself before launching again. The transitions were smoother now—a wave, not a cliff—and his Core hummed with the effort, each orbit resonating with the others.
Sight mapped the walls, the angles, the distances. Hearing tracked the sounds of his own movement, the way his mass affected the acoustics of the space. Touch felt the texture of the floor beneath his boots, the way it changed as he added and removed weight. Weight conducted the orchestra, the first among equals, the orbit that had been with him the longest.
By the end, the bunker's training area looked like it had hosted a very localised earthquake. Craters pocked the floor in a pattern that traced his circuit—a spiral of destruction that started small and grew wider as his control improved. The walls bore boot-shaped impressions where he'd landed and pushed off, each one a testament to the forces he was learning to command. One section of ceiling had collapsed entirely, the metal fatigue too much for a structure that was never designed to contain an Orbiter discovering what weight really meant.
Cael sat in the middle of the destruction, breathing hard but grinning. His body ached—every muscle, every joint, every bone—but it was a good ache, the ache of a tool that had been used for its intended purpose. His Core hummed with the pleasant fatigue of a muscle pushed to its limit and finding that the limit had moved.
---
"You know what the scary part is?" Lyra said, surveying the damage from the doorway. She had her arms crossed, her weight on one hip, her Hindsight flickering as she tracked the echoes of Cael's movement through the destruction. "He's been doing this for three weeks. Most Orbiters take years to get Weight control this fine."
The Hermit said nothing for a long moment. He was looking at his monitors—the ones that tracked Cael's orbital output in real time, measuring the power signatures of each active orbit against historical baselines. The screens showed waveforms that climbed higher with each passing day, each training session, each breakthrough.
The boy's growth was exponential.
"His rate of growth is accelerating," the old man said quietly. Not to Lyra, not to Cael. To himself. To the data. To whatever mathematical models lived in his head that kept him one step ahead of catastrophe. "The intervals between new orbit activations are shortening. The power output of each orbit is increasing faster than the previous one. If the pattern holds…"
He didn't finish the sentence. He didn't need to.
"Is that bad?" Cael asked.
The Hermit turned off the monitor. The screen went dark, its blue glow fading to grey, and for a moment his face was lost in shadow. "It's unprecedented. The question of whether it's bad depends entirely on what happens when you reach orbit thirteen."
The room went quiet. Even the bunker's mechanical hum seemed to hold its breath—the air recycler, the water pumps, the Hermit's life-support machines, all of them pausing in their eternal cycles.
"I won't open it," Cael said. His voice was steady, but there was something underneath it—a tremor, a crack, the sound of a conviction that had been tested and was still holding. "The door. I won't open it."
The Hermit looked at him with eyes that had seen too much and forgiven too little. Eyes that had watched the world break and had spent twenty years trying to put the pieces back together. "The door doesn't need you to open it, Cael. It needs you to exist near it. And every orbit you unlock makes you a little more like a key sliding into a lock."
He paused. His three-fingered hand rested on the arm of his chair, the fingers curled, the knuckles pale.
"The question isn't whether you'll choose to open it. The question is whether it will choose to open through you."
---
Cael looked at his hands.
They were steady. Strong. Capable of crushing stone or floating on air, of cutting through steel or feeling the truth in a person's heart. They had been janitor's hands once—calloused from mop handles, scarred from broken glass, stained with cleaning chemicals that never quite washed off.
They were still those hands. But they were something else now too.
And somewhere deep inside them, in the place where the thirteenth orbit slept, something that was not quite him stirred in its dream and smiled.
---
That night, Cael lay in his cot and practised feeling his own weight.
Not the physical weight—the emotional weight. The density of his own truth, his own intentions, his own secrets.
He found layers.
On the surface: determination. The hard, bright shell he showed the world, the thing that kept him moving when he wanted to stop. This layer was thick, well-formed, the result of years of being told he was broken and refusing to believe it.
Beneath that: fear. Not the sharp, panicked fear of the tower closet—something deeper, older. The fear of being alone. The fear of losing the people he was starting to care about. The fear that the Hermit was right, that the door would open through him whether he wanted it to or not.
Deeper: grief. The grief of a six-year-old who had watched his parents walk into the light. The grief of a seventeen-year-old who had spent eleven years carrying that memory alone. The grief of a boy who had finally found something like a family and knew, with the certainty of someone who had lost before, that he would lose them too.
And at the very bottom, beneath everything else, so small he almost missed it:
Hope.
Not the thin, fragile hope of the Hermit's frost—something warmer. Something stubborn. The hope of a boy who had been told he was nothing and had decided to become something.
Cael pressed his palms against his chest, over his Core, and felt the thirteen orbits spinning inside him. Twelve active, one sleeping. Twelve bright, one dark.
I won't open you, he thought. Not unless I have to.
The thirteenth orbit pulsed—once, twice—and settled back into its dreaming.
The whisper was silent.
---
The next morning, the Hermit announced that they would begin work on Binding.
"The orbit of gravitational connection," he said. "The ability to hold things together, to create bonds that gravity itself respects. It's the opposite of Edge. Where Edge separates, Binding unites."
"What can I bind?" Cael asked.
"Anything. Two objects together. A person to the floor. A door to its frame. A wound to its healing." The Hermit's voice was quiet. "Binding is the orbit of care. Not control—care. You can't hold something together unless you understand what it wants to be."
Cael thought about Lyra's grief, the black diamond at her centre. He thought about the Hermit's guilt, structural and load-bearing. He thought about his own hope, small and stubborn and alive.
"I want to learn," he said.
The Hermit nodded. He set up a series of objects—two stones, a broken piece of metal, a torn sheet of paper—and explained the theory.
Cael listened. He practised. He failed. He practised again.
By the end of the day, he could hold the two stones together with a gravitational bond that was stronger than glue, more permanent than welding. He could feel the connection between them—a thread of gravity that pulsed with his heartbeat, responsive to his will.
Seven orbits active. Six to go.
And the thirteenth, waiting in the dark.
---
That night, the whisper spoke.
Binding, it said. Interesting choice. The First Core never mastered Binding. He was too focused on separation—on cutting, on breaking, on pushing. He didn't understand that connection is the foundation of gravity.
What do you know about the First Core? Cael asked.
Everything. I was there.
You're not the First Core.
No. I'm what's left of him. The part that survived the void. The part that remembers.
Remembers what?
What it felt like to be human.
The whisper was quiet for a long time. When it spoke again, its voice was softer—almost gentle.
The Hermit is right to be afraid, Cael. The door will open through you if you're not careful. But he's wrong about one thing.
What's that?
The door doesn't want to destroy you. It wants to complete you. The same way the First Core was completed. The same way everyone who walked into the light was completed.
That's not completion. That's consumption.
The whisper didn't answer.
Cael lay in the dark, feeling the weight of his own hope, and wondered if the difference between consumption and completion was just a matter of perspective.
He didn't sleep well that night.
But he didn't dream of the void either.
He dreamed of his mother's hands, stirring soup, and the kitchen was warm, and the light coming through the window was golden.
It was almost enough.