The Pulse They Withheld

The crew gathered around the basin with the selector’s cost between them. Orra could feel it in the way nobody reached for the keel-instrument.

Beyond the island’s cliff, the chain disappeared into the Aethersea. Its links were dimly visible through the mist, descending in a straight line until the glow swallowed them. The *Morrowfin* rested on its jury sail above the landing shelf, fore rigging bare and one lift crystal still dark. They had brought the ship this far by careful work. They would not have a quick escape if the ring’s response turned violent.

Nima laid her astrolabe across the basin’s rim. Three of its thin arms trembled over the carved routes. “The ring will send the next pulse down whichever channel the selector gives it. One pulse diverted means one pulse withheld from the chain.”

Brask leaned on the basin’s edge, watching the chain below. “Then we find out whether the thing on the other end minds being ignored.”

“That is a very cheerful way to describe it,” Nima said.

“I’ve had worse descriptions.” Brask glanced at Orra. “Mostly from captains.”

Vey did not join the joke. He stood at the inland side of the basin, hands clasped behind his back. “If the hull moves, we leave. No second test. We don’t wait around to see how much the chain can take.”

Orra studied the three routes cut into the stone. The chainward groove held a weak, steady gleam. The uncharted branch remained dark. A short pulse from the ring could tell them whether anything on that route could answer. It could also leave the hull without the tightening that had kept its movement checked.

She had watched the chains draw taut before. She had watched the mass inside the curve move under their pull. The thought of choosing to let it shift sat badly in her hands. She flexed her fingers once, then set them against the cold stone.

“If we send it,” she said, “we send one pulse. Nima watches the return. Brask watches the chain. Vey keeps the ship ready to lift.”

Vey’s eyes stayed on her. “And if the chain gives?”

“Then I put the selector back and we leave.”

He nodded, accepting the limit. “One pulse.”

Orra took the keel-instrument from Nima. The brass was familiar against her palm, its blunt keel edge worn smooth from use. At the ring beneath the cliff, it had fit the socket like a key. Here, it would give the selector its direction. Orra set the instrument into the basin’s central groove and waited for the carved routes to take its weight.

The basin brightened. The chainward pillar lit first, then the inland route. The uncharted pillar kindled last, pale and thin. Nima turned one astrolabe arm until it aligned with the new light.