The Frequency

They went on a Thursday morning.

Not into the trees — Morganta had been clear about that and hadn't softened it and nobody had pushed back with any real force, not even Ro who had been quieter since the night on the road in a way that read less like withdrawal and more like someone who had recalibrated something internally and was still adjusting to the new setting. What they did on Thursday morning was go to the edge. The tree line. Close enough for Priya to set up inside the first layer of the woods, technically within the forest but only just, near enough to the road that the cars were still visible through the trees behind them.

Morganta had agreed to this after a long conversation with Lexus the previous evening that had covered everything Nina had told her in the kitchen — the Portuguese settlement, the Norwegian account, Adaeze's theory about the exempted person, all of it. She'd told him everything the way she'd told herself she would, plainly and in full, and he'd listened the whole way through without interrupting and then sat quietly for a while and then said what he thought, which was that he didn't like any of it but that he understood why they couldn't stop now. That was always his way — honest about the discomfort, clear about the commitment. It was one of the things she'd loved about him from the beginning and still did.

They'd agreed on boundaries together. No deeper than fifty metres into the trees without Morganta present. No solo work inside the tree line. Morganta and Lexus would stay at the outer edge while Priya set up the equipment. Callum would manage the data from outside the tree line entirely, sitting in the car with the laptop. Nina would stay with Callum. Ro would stay with Nina.

Ro had agreed to this without the resistance Morganta had been braced for, which either meant she'd genuinely accepted it or meant she was picking her moment, and Morganta kept both possibilities in mind with equal weight.

It was cold that morning. The kind of cold that comes in autumn when it means business, the air sharp and flat and still, the light thin and grey. The tree line looked the same as it always looked from the road — dark, dense, the trees pressing close to each other with that quality of accumulated age that old forests have, where the space between the trunks feels inhabited even when nothing visible is there. Morganta stood at the verge and looked at it for a moment before they started moving. She did this every time she came to this road now. Just looked. Let her eyes and instincts tell her whatever they were going to tell her before she stopped paying attention to them and started paying attention to tasks.

The trees looked back, the way the trees always seemed to look back when you stood at this particular stretch of road. She wasn't being fanciful about this — she'd thought about it practically, about whether what she experienced as the trees looking back was a projection, her own knowledge of what was in there being thrown outward onto the neutral surface of the forest. She still didn't know for certain. She'd decided it didn't matter. Whether it was projection or something else, her response to it was the same: careful, steady, awake.

She nodded at Priya. They went in.

The first thing that changed inside the tree line was the sound.

It happened within ten metres. The ambient noise of the road — the occasional car, the wind in the open space of the verge, the general low texture of a morning with countryside sounds in it — dropped away almost completely, replaced by a different quality of quiet. Not silence exactly. The forest had its own sounds, the small sounds of old trees in a light wind, something moving in the undergrowth thirty metres to the left, birdsong much higher up and far away. But the quality of quiet underneath all of it was different from the quiet outside. Thicker, Morganta thought, and then rejected the word because it was imprecise. More present. Like the air was paying attention.

Priya moved with focused efficiency, unpacking the directional microphones from the case she'd carried in and setting them up in the configuration she'd designed based on the previous night's data. She worked quickly and quietly and her hands were completely steady, which Morganta appreciated. She'd asked Priya directly the previous day whether she was comfortable coming inside the tree line and Priya had said yes with a brevity that didn't leave room for doubt. She wasn't cavalier about it — she'd heard everything Morganta had told the group, understood what the trees represented — but she operated in a specific mode when she was working that placed the task at the centre and managed everything else around the edges of it.

Morganta stood a few metres back and watched the tree line ahead. Lexus stood beside her, slightly to her left, turned slightly outward from her so they were covering different angles without having discussed it — it was the kind of automatic complementary positioning that came from two years of working alongside someone in situations that required it.

The frequency was present.

She could feel it more than hear it. A low vibration at the edge of sensation, not unpleasant exactly, more like standing near a very large machine that isn't making much noise but is making some, a feeling in the chest more than the ears. She'd felt it on previous visits to the road but not like this — not with this clarity, not this distinctly separable from the ambient sound around it. Inside the tree line it was unmistakable. A consistent, patient, low pulse that didn't fluctuate, didn't respond to the wind or the movement of the three of them through the space.

"You can feel it," Priya said. Not a question, she was watching Morganta's face.

"Yes," Morganta said.

Priya glanced at her equipment. The levels were already showing something on the displays even before she'd finished setting up. "It's stronger in here," she said. "Significantly." She adjusted one of the microphone stands. "Which confirms that what we were getting from the road was attenuated. The true signal is louder than we thought."

"How much louder?" Lexus said.

Priya looked at her displays for a moment. "I'll need to run the proper analysis but preliminary—" she paused, looking at the levels "— I'd estimate twice the amplitude we recorded from the road. Maybe more."

Morganta looked ahead into the trees. The ground fell away gradually from the road, a gentle slope downward, and about a hundred metres in the terrain changed — she could see it from here, the way the canopy altered, the trees becoming larger and older looking, the undergrowth thinning. Beyond that the ground dipped further, she knew from the topographic map, into the depression Priya had identified. She couldn't see it from here. But she could feel something from the direction of it. A quality to the frequency that had a directionality to it now that they were inside the tree line, a sense of it coming from somewhere specific rather than everywhere at once.

That was different. On the night of the clearing, the sound had been omnidirectional, sourceless, impossible to orient against. Inside the tree line, at least from here, at least now, it had a direction. She wasn't sure what to make of that.

She turned and looked back. The road was visible through the trees, a pale strip of tarmac in the grey morning light, Callum's car on the verge with the laptop visible through the windscreen. She could see Callum's shape and Nina's and between them, in the back seat, the outline of Ro sitting very still.

She turned back to the trees ahead.

"How long do you need?" she said to Priya.

"An hour," Priya said. "Maybe ninety minutes."

Morganta nodded. She looked at Lexus. He was looking at the ground between them and the depression, the slope of it, the older trees. She recognised the expression on his face — not fear, not reluctance, something more precise than either. The expression of someone weighing things accurately.

"Walk the perimeter?" he said. Meaning the perimeter of where they'd agreed to stay, the fifty metre boundary.

"Yes," Morganta said.

They walked it slowly. Not speaking much, just moving through the space inside the agreed boundary with their eyes open and their attention outward, covering the ground the way you cover ground when you're not sure what you're looking for but you're sure you'll know it if you find it.

They found it at roughly forty metres in, toward the northern edge of their boundary.

It wasn't dramatic. That was the thing about this place — nothing presented itself dramatically. Everything arrived quietly, understatedly, requiring you to look at it twice and then a third time before the wrongness of it resolved.

Lexus saw it first. He stopped walking and Morganta stopped with him and followed his eyeline.

The trees here were older than the ones near the road. Much older — the trunks wider, the bark darker and more deeply furrowed, the canopy far above them dense enough that the light underneath was different, dimmer, with a greenish underwater quality. These trees had been here a very long time. That was clear just from looking at them.

What wasn't immediately clear, and then became very clear, were the markings on the trunks.

Not recent markings. Not carvings or graffiti or anything that could be attributed to people who'd been through here recently. These were old. Very old. Worked into the bark deeply enough that the bark had grown around the edges of them in places, partially absorbing them, the way bark absorbs things over decades. The markings were not identical on every tree — they varied in their specific form — but they shared a quality, a family resemblance, a consistency of intent that said they had been made by the same impulse even if not the same hand or the same time.

Morganta crouched in front of the nearest tree and looked at the markings closely. She didn't touch them. She looked at them the way she looked at evidence — carefully, without assumption, letting them be what they were before deciding what that was.

They weren't letters. Not any alphabet she recognised. Not symbols in any conventional sense either — not circles or crosses or the kind of markings you see in archaeological contexts that have known meanings. They were more organic than that, more irregular, like something had pressed against the bark and left an impression rather than something having been deliberately carved. The shapes had a flowing quality, connected at the edges, running from one into the next in a way that almost suggested continuous script if you tilted your head and let your eyes go slightly soft.

Lexus crouched beside her and looked. "Callum's historical records," he said quietly. "He mentioned markings."

"He said they matched descriptions in two of the oldest cases," Morganta said. "I want him to see these."

She took photographs. Multiple angles, close and further back, with her hand in frame for scale. She took a video, slow, sweeping from one marked tree to the next and the next, capturing the extent of them, the way they continued through this section of the forest, tree after tree, the markings running along the trunks at approximately eye height, as though whatever had made them had been standing at approximately human height.

She counted ten trees with markings visible from where they stood. She suspected there were more.

"How old," Lexus said. Not a question exactly, more thinking out loud.

"I don't know," Morganta said. "Old." She looked at where the bark had grown over the edges of the markings on the nearest tree. "Decades at minimum. Could be much longer."

They stood up and looked at the marked trees and beyond them where the ground continued its slope downward toward the depression. From here, at the northern edge of their fifty metre boundary, the bottom of the depression wasn't visible but its presence was. The air was different in that direction. Not visibly, not in any way a camera would capture or a measurement would clearly quantify. Just a quality to the air, a weight to it, the way the air feels different in a room where something significant has happened even after the thing is gone.

The frequency was stronger from that direction. Noticeably stronger. Morganta could feel it as a distinct physical sensation now, low in her sternum, a vibration that wasn't quite sound and wasn't quite feeling but sat at the border between them.

"We don't go further," Lexus said. Not to her specifically. To both of them. A reminder that applied equally to both of them.

"We don't go further," Morganta agreed.

She took a few more photographs of the marked trees and then they walked back to Priya.

Priya was in the middle of something when they returned. She had her headphones on and was watching her equipment displays with the focused stillness of someone receiving information they need not to interrupt. Morganta and Lexus stood back and waited. After a few minutes Priya took the headphones off and looked at them.

"The acoustic profile is completely different inside the tree line," she said. "The frequency is structured differently in here. From the road it presented as omnidirectional — coming from everywhere, no identifiable source direction. In here it has a clear directional component pointing toward the depression. It's like—" she paused, looking for the right analogy "—like hearing a signal through a wall versus being in the same room as the source. Same signal, completely different experience of it."

"What does that mean in terms of what's producing it?" Morganta said.

"It means the omnidirectionality from the road was an artefact of how the signal was propagating through the trees," Priya said. "The trees were diffusing it, scattering it in all directions. Inside the tree line the signal has its natural directionality. Which means—" she looked at her displays "—the source is almost certainly a point source. One location. Not spread through the forest. Coming from one place."

"The depression," Morganta said.

"Yes," Priya said.

She told them about the markings. Priya listened with attention and then asked to see the photographs, which Morganta showed her on her phone. Priya looked at each one carefully. "Acoustic markers," she said, almost to herself.

"What?" Lexus said.

Priya looked up. "I'm speculating," she said. "But the placement — eye height, along the trunks, in a line leading roughly toward the depression. In acoustic terms, if you wanted to mark a path toward a sound source for someone who could hear the signal, this is approximately how you'd do it." She looked at the photograph again. "Or if you wanted to warn them away. The markings could be either."

Nobody answered that. The question of which one it was sat in the air between them without resolving.

They packed up the equipment at the end of Priya's ninety minutes and carried it back out to the road. The relief of crossing back over the tree line was something Morganta felt in her body before her mind had processed it, a physical easing, the particular quality of the air outside the trees being different from the quality inside. She stood on the verge and breathed for a moment.

Callum was already out of the car when they emerged, waiting, and he saw the expression on her face and said nothing and took the equipment case from her and carried it to the car.

Nina came to her. "Alright?" she said.

"Yes," Morganta said. She looked back at the tree line. At the dark consistent line of it against the grey sky. "We found markings," she said. "On the trees inside the boundary. I need Callum to look at the photographs."

Nina nodded. "Inside," she said, meaning the car, meaning they should get off the road and away from the tree line before they discussed this. Morganta agreed with that instinctively and moved without arguing.

Ro was the last out of the car. She'd been sitting in the back seat for the full duration, which was nearly two hours, without — as far as Morganta could tell — moving much. She stood by the car and looked at the three of them emerging from the tree line with an expression that said she'd been doing an enormous amount of internal work during those two hours and had arrived somewhere she hadn't started from.

She looked at Morganta. "You found something," she said.

"Yes," Morganta said.

"Something that's been there a long time."

Morganta looked at her. "How do you know that?"

Ro looked at the tree line. "Because I could feel the age of it from here," she said simply. "Sitting in the car. Just the age of it." She paused. "Is that—" she stopped and seemed to reconsider the question. "Never mind."

"No," Morganta said. "Say it."

Ro looked at her. "Is that normal? Being able to feel it from outside the trees?"

Morganta looked at her steadily and thought about what honest answer she had for that. She thought about what Nina had told her about the selection mechanism, about the extended contact period, about what made someone reachable. She thought about Ro waking up at midnight and following a voice to the tree line without making a conscious decision.

"No," she said. "It's not normal." She held Ro's gaze. "It means something. I don't know exactly what yet. But it means something and I need you to tell me when it happens. Every time. Whatever you feel, whatever you hear, you tell me."

Ro held her gaze for a moment. Something passed through her expression that was too quick and too complicated to fully read. Then she nodded. "Every time," she said.

They got in the cars and drove back toward Kingsport and nobody spoke much on the drive, everyone processing in their own private way the two hours inside and outside the tree line and what had been found and felt and heard and what it was going to mean for what came next.

Morganta drove and watched the road ahead and thought about point sources and marked trees and a depression in the ground that she hadn't seen yet but could feel the direction of from forty metres away. She thought about Adaeze Obi spending thirty years building a picture of something that moved across centuries and continents, arriving and settling and eventually leaving, and the question she'd never answered: what makes it stop.

She thought about the exempted person going back in.

She thought about coming back out quieter.

She drove and the road unreeled ahead of her and in the rearview mirror the tree line receded and then turned with the road and was gone, and the grey morning sky sat over everything, flat and still and giving nothing away.