The second one didn't wait to be approached.
It came from the left wall — through it, which the classification system said was not possible at this density — and it was fast. Faster than the first by a factor Kai's instinct measured in survival terms before he'd consciously processed the movement.
He pulled Orin sideways. The Null Field snapped to Erasure-ready. The construct stopped.
Not because he'd threatened it. Because the motion of pulling Orin had put the two of them in contact — shoulders, briefly — and the overlapping resonance of their classes had spiked into something visible even at this depth.
The construct was looking at that.
"Don't move," Kai said.
"Already not," Orin said.
Three seconds. Four. The construct's signature was different from the first — younger, somehow, which was not a word that mapped correctly but was the closest available. Less patient. More volatile. The learning process is not safe.
It lunged.
Kai didn't erase. He displaced — a function of the Null Field he'd discovered in the third week of his second year, which created a pocket of null-space that constructs moved through rather than into. The construct hit the pocket, registered the absence, and recalibrated in mid-movement. Not confused. Adapting.
It lunged again. He displaced again. Beside him Orin had gone into the stillness-that-was-not-frozen, his Voidwalker class reading the construct's movement geometry, threading its trajectory through spatial logic.
"Left," Orin said.
Kai went left. The construct's third lunge passed through where he'd been standing. The null-pocket collapsed behind him with a sound like a held breath releasing.
The construct landed. Turned. And then — stilled.
Because the displacement had done something Kai hadn't intended: it had shown the construct what the Null Field could do without being a threat. Not the absence of power. Precise, deliberate restraint. The class signature of something that could erase and had chosen not to.
The construct's signature shifted. Same pressing-against-glass quality as the first, but faster. Urgent. Learning at a pace that the Origin Log's careful, measured prose had not quite conveyed.
Kai let the Null Field breathe into it. Let it read.
Forty seconds of silence. The passage held around them — no further constructs at range, the Source signal steady from below.
The construct made the same harmonic as the first. Lower pitch. Different question.
"It's asking something," Orin said.
"I know."
"Can you answer it?"
Kai looked at the construct. It pressed its signature against his Null Field with the quality of something that had been in the dark for sixty-one years and had just found a window.
"I think I just did," he said.
The construct moved back. Slow this time. Almost reluctant. Into the left wall, and gone, and the passage ahead opened into something wider and older that the Source signal rose from like heat from deep stone.