The second segment cost seventy-three percent.

He surfaced at twenty-seven percent remaining and sat in the eastern scrubland’s morning and did the arithmetic. The adapted grammar wasn’t stabilising between segments the way standard chain grammar had. Each time he descended, he had to re-establish the connection between the chain infrastructure and the entity’s asymmetric nodes from near-scratch—the carrier function holding a custom geometry rather than slotting into a known template that the substrate remembered.

Two segments in. Two days of build at seventy-plus percent per session. At this rate, a chain that should take twelve segments takes twelve days of single-segment work. Slower than the western chains by a factor of three. That’s the cost of adapted grammar without a template. File it.

He told Soren.

Soren looked at his instruments rather than at Kai. "Yes. The adapted anchor geometry requires active maintenance throughout each session—you’re not just building, you’re holding the connection’s shape while you build. That’s a sustained draw rather than a construction draw." He made a notation. "If you can establish a partial template from the segments already complete, subsequent segments may cost less. The substrate should begin accepting the custom geometry as it would accept standard grammar, eventually."

"How many segments for that?"

"I don’t have data for this. Nobody does." He didn’t look apologetic about it. "Four segments would be my estimate. After that the carrier function should have enough established geometry to reference rather than reconstruct."

Four segments at seventy-percent draw each. Then cheaper. Four days minimum before the cost starts dropping. With standard recovery between sessions, manageable. Not fast. But the entity has been here twenty years. It can wait another two weeks.

Neral was writing the new documentation section in the long stretches between Kai’s descents. He had filled eight pages by the end of the second day.

"The critical distinction," Neral said, not looking up from the page, "is that standard chain grammar assumes the entity will adapt to the chain’s infrastructure during the connection process. The entity adjusts its architecture to meet the road network’s standard. Here the chain adapts to the entity. That’s the reverse of every previous documented chain build." He wrote another line. "Future carriers need to understand: some entities won’t adjust. Some entities developed in conditions so different from the western road network’s assumptions that asking them to adjust is asking them to rebuild twenty years of sophisticated management work. Don’t ask them to. Build to them."

He finished the paragraph and looked up.

"I’m calling this section Adapted Infrastructure. The western documentation is Established Infrastructure. That distinction needs to be clear from the first page."

Third day. Third segment.

He descended with the pool at one hundred percent and the source active in the formation layer below. Familiar geometry now—the three nodes, the asymmetric axis, the way the carrier function had to hold the connection’s shape actively rather than letting the template do it. Third segment. Third time through the custom geometry.

At the six-minute mark something changed.

Slight. Not a shift in the entity’s architecture—the entity was unchanged, as patient and precise as it had been throughout. A shift in the substrate around the two completed segments. The rock itself had begun adjusting to the geometry—the same gradual substrate acceptance that had made every previous build easier as it progressed, but slower this time, working with a less familiar shape.

He built the third segment into it.

Sixty-eight percent draw. Down from seventy-three. Soren was right about four segments. Third is already cheaper. Fourth should drop further.

He surfaced at thirty-two percent.

The creature that had been following them for two days came at him from the eastern treeline while he was still sitting by the Rift.

Different from the one he’d killed the first night. Lighter body, longer reach, the six limbs all adapted for movement rather than striking. It had been ranging the scrubland since the second morning—he’d caught its substrate read twice before it had retreated. Patient. Watching.

He activated Dragon Predator Mode at formation-layer depth and read before it closed the distance.

Two nodes, not three. Different formation-layer pattern from the first creature—the energy signature ran along the spine rather than concentrating in limb and thorax. Built for sustained pursuit rather than burst-striking. This was something that waited and ran things down.

He had thirty-two percent pool.

Thirty-two percent. Not ideal. The formation-layer read is clearer than it would have been a week ago, which helps. Two nodes, spine-distributed. Impact Frame will cost less than it did against the first creature—this one hits lighter and more often rather than heavy and few.

It came in fast. He activated Impact Frame and let it hit, reading on contact.

Spine-distributed. The energy cycled up from the lower node to the upper and discharged at the strike point. He read the cycle’s rhythm in the contact. About three seconds between discharge peaks.

Piercing Authority—targeted at the lower spinal node during the discharge cycle’s low point, between peaks. The creature’s energy cycle stuttered.

Predatory Burst Step disengaging, creating two metres of distance, long enough for the cycle to try to rebuild.

He read it rebuilding.

Piercing Authority again at the low point. Second stutter. The creature’s movement slowed—not injury in the conventional sense, the energy cycle disrupted enough that its coordination was affected.

Rending Strike at the upper node on the third approach. The cycle broke. It went down without the forty-second struggle the first one had cost him.

Pool at fourteen percent. That was as efficient as the fight was going to get with two-thirds empty at the start. Formation-layer depth read made the difference—cycle rhythm, node positions, optimal strike timing. Wouldn’t have had that from standard Dragon Mode depth. Would have taken twice as long and hit the same endpoint at zero.

The older man started on the creature without being asked. He had a practical relationship with eastern wildlife that he hadn’t bothered to explain.

Mira had been reading the vault pair through the fight.

"The entity tracked it," she said. "The substrate pressure changes when you fight—I said this before. But this time the entity’s signal shifted while you were reading the creature, before the contact. It reads the formation layer below. It’s been below this Rift for twenty years—it knows the eastern fauna’s substrate signatures." She held the shells. "It was watching."

He considered this.

Entity that lives in the formation layer, reads formation-layer energy signatures, has been watching eastern fauna move through its substrate for twenty years. It knew what the creature was before he did. Useful information to have filed. At seven signals, the vault pair was reading it like a known quantity. It was.

He recovered through the afternoon. Pool at sixty-one percent by evening.

Not enough for a descent. Tomorrow.

He sat with the carrier function open and read the three completed segments below. The substrate was still adjusting—slowly, but the geometry was becoming familiar to the rock the same way the lateral stage segments had become familiar to the rock, the same way every carrier-built infrastructure eventually stopped requiring active maintenance and became part of the substrate’s own structure.

Slower than standard grammar. But the direction was right.

Neral was still writing. The new documentation section was twelve pages and growing. 𝙛𝒓𝓮𝒆𝔀𝒆𝙗𝓷𝒐𝙫𝒆𝙡.𝒄𝓸𝓶

He looked east. The formation-layer read extended further now than it had before the first creature fight—Dragon Mode at formation depth had been running for three days and the integration was settling in the way new capabilities settled, the way the Source Point integration had settled after the first eastern build. What had required effort to hold was becoming available passively.

Depth extended and stabilising. The eastern substrate’s architecture is readable without forcing the read. That’s going to matter for the sixteen formation zones. And for whatever else is out here that nobody has mapped.

He lay down.

The source was steady in the deepest layer. The entity was below, alert, with three segments of a chain that fit.

Tomorrow, the fourth. Then cheaper.