The Signal

The workshop was loudest in the morning.

Jolt was usually testing something before anyone else arrived. Rivet showed up already smudged. Cogs ran his calibrations - quiet, methodical, unhurried. Whirry opened the east-facing vents and let the hum of Pixel City in.

Tinker was usually there before any of them. He didn't need much sleep. This morning he was sitting at the center table with his notebook open and his hands folded on top of it, waiting. Not working. Just waiting. Cogs noticed immediately.

"What's in the notebook?" he asked.

"Twenty-two mornings," Tinker said. "Same reading. Every time."

He put the notebook in the middle of the table.

Cogs turned it slowly, reading each entry in order. Jolt lasted about four seconds before coming over and leaning over his shoulder.

"It's tiny," Jolt said.

"It's consistent," Tinker said.

Rivet came over from his work bench. "What's consistent?"

"A signal I've been tracking for twenty-two days. It's small. At first I thought it was just a measurement error, but it's there every day."

"It's gotta be coming from somewhere in the shop," Whirry said.

"I've checked everything inside the workshop. South panel, backup transformer, old battery cells in the storage room." Tinker ticked them off on his fingers. "It's not in here. Something outside is pulling on the whole grid. Not one line. Everything. Same small amount, every morning."

A pause settled over the workshop.

"So we find it," Jolt said.

"We find it," Tinker agreed. "The question is how."

Jolt went first. "Static. If something outside is generating a consistent signal, it'll disturb the charge in the air around it. We walk outward and monitor as we go. When the readings start climbing, we're getting close."

"On a weak signal, the static will be even weaker," Cogs said. He was already sketching something. "If I can plug into the power terminals along the main grid and take hard measurements at each one, I can map the signal's gradient. Triangulate the source."

"That could take all day," Rivet said.

"We can trace it while we walk," Tinker said. "Wire a tracer into the wireless grid tap and it'll show the direction of the drain in real time. Follow it outward from the city."

"So - a compass," Rivet said.

"A compass that reads the grid instead of magnetic north."

Rivet nodded. "Then give it a compass interface. A needle. Something we can look at without stopping every ten minutes."

They all looked at him.

"What? You want to read numbers off the screen the whole time?"

They all nodded. He was right.

Whirry had been quiet through all of this, her panels shifting between copper and gold. "It should trace the grid and measure static and plug into the terminals and have a compass needle," she said. "One instrument. Everything built in."

"That's four things," Jolt said.

"It's one box," she said. "You each know your part. Build them together." She paused. "And while we walk - we listen. The machines near the source won't sound quite right. They drag. They compensate." She looked at each of them. "The instrument shows us what to measure. It doesn't do the measuring for us."

Nobody argued with that.

They built it in a day and a half.

The compass needle kept pointing at Jolt, which made everyone laugh. Rivet had to add a calibration filter three times before the needle stopped following him around the room.

"It's not a flaw," Jolt said. "It's just accurate."

"It needs to point at the signal," Tinker said, making an adjustment with a tool too small for anyone else to comfortably hold. "Not at you."

"Those aren't mutually exclusive-"

"Jolt, are you saying you're the source of the signal?"

"We have no idea, so it could be one of us!"

Everyone just stared at him in disbelief.

"Right. Fine. It's probably not us."

By the following morning, the instrument was ready. Not elegant - a compact brass housing with a glass face, a needle that swept between zero and ten, terminal leads on a short cable, and a static sensor along the top that Jolt had insisted on building himself. It worked. That was what mattered.

They set out the next morning, Tinker carrying the instrument and Cogs carrying the map.

The Spark Lands were loud near the center. The main rail line crackled. Workshops rattled. Steam vented from the upper fabrication district in long white columns. The needle sat at two. Nothing new.

They stopped at the first terminal - a squat copper pillar at the edge of the market district. Cogs crouched down, connected the terminal lead, and took a reading. "Slightly elevated in this direction," he said. "Not much. But it's there."

"Static is up half a unit since the workshop," Jolt confirmed, looking at the screen of the device.

"The machines on this block are running a little fast," Whirry said. "I can hear it. Like they're compensating for something they can't keep up with."

They kept walking.

Second terminal. Third. The needle climbed past three, past four. The workshops gave way to storage sheds. The storage sheds gave way to the flat fields of the Spark Lands where the copper rails thinned out and the ground turned to rough stone. The noise of the city dropped away behind them.

"Static is three units above baseline," Jolt said.

The needle was at six.

"I can hear it," Whirry said. "The machines behind us are all pulling in this direction. Like a current."

Cogs checked the map. They were past the last terminal point. "We're off the grid now," he said. "No more fixed readings."

"Needle only from here," Tinker said.

He looked down to check it.

The instrument sparked, the screen flashed three times, then it went dark.

Tinker tapped it. Nothing. He opened the casing - Rivet was immediately beside him, looking too.

"Burned out capacitor." He closed the casing. "Did we bring any spare parts?" They all looked back and forth between one another.

"We could go back. Get the parts." Cogs said eventually. Not suggesting it - just naming the option.

Jolt checked his own internal static sensor. "We're close. Whatever it is, it's right out there."

"We can still feel it. Barely," Whirry said.

"Let's keep walking," Rivet said. "We'll figure out something."

"This area is huge," Jolt said.

Rivet just shrugged and walked off into the field.

It was Rivet who found the robot.

Half-buried at the base of a low rocky shelf, face-down, one arm extended like it had been pointing at something when it stopped. Ancient. Built from materials none of them knew. Not functional. But whole.

"How long do you think this has been out here?" Jolt asked.

Nobody answered.

Whirry crouched beside it. "Look at the direction it fell," she said. "It was walking the same way we are."

Tinker looked at the robot. He looked at the dead instrument in her hand. He looked at Rivet.

Rivet had already seen it. "The power cell," he said. "We pull it and wire it to this thing, we might get it running."

"For how long?" Cogs asked.

Tinker calculated. "Sixty seconds. Maybe less. It's a big machine."

The silence was short.

"Then we need to know what we're asking before we start it," Cogs said.

They all started talking at once.

Jolt wanted to know about the signal. Rivet wanted to know if there was any danger. Tinker wanted to know how whatever was giving off the signal was built. Cogs wanted to know who built it and when. The words piled on top of each other until none of it was making sense.

"Stop," Whirry said.

They stopped.

"Sixty seconds. What do we actually need to know to find it?"

A shorter silence.

"Where it is," Tinker said. "Exactly."

"What it does," Cogs said.

"Whether it's safe to approach," Rivet added.

"Who built it," said Jolt. More quietly.

"Four questions," Whirry said. "Ask them fast. Let it answer."

Tinker opened the robot's chest casing. The power socket was an older design - different shape, different wiring - but close enough. Rivet stripped the wires of the battery cell and handed it to Tinker. He connected it.

The robot's eyes opened.

"We have very little time," Tinker said immediately. "We're following a signal - old, consistent, humming. There's something out here sending it. Where is it?"

The voice was slow, like something waking from a long sleep. "The ridge," it said. "North face. Stone outcropping. You are... close."

"What does it do?" Cogs asked.

A pause. The eyes flickered. "It calls. It was built to call."

"Call what?" Jolt asked.

"Something that does not come when called." Another pause. "It has been trying. For a long time."

"Who built it?" Rivet asked.

The robot's eyes were dimming. "Someone who came from outside. Who believed the calling would work. Who left before..."

The eyes went dark.

Five inventors stood in the quiet stone landscape with sixty seconds of clues.

Tinker disconnected the cell. "North face," he said. "Stone outcropping. Let's go."

It was small and very old. Settled into the base of a low ridge like it had grown there - dusty, dull at the edges. No markings. No indication of purpose from the outside.

But it was running.

The hum was faint and would have been easy to miss anywhere louder. Out here it was clear. A steady low note.

Between them and the structure: machinery. Old pylons, dormant conduit, rings of interlocked gears, completely surrounding the structure in a circular ring. Cut through from the outside to the center was a path. Thirty steps. Wide enough for all five of them.

"That's convenient," Rivet said.

"Too convenient," Tinker said.

Jolt took one step toward the path.

The machinery moved.

Not loud, but quickly. Gears turning, pylons angling, conduits sliding into place - and in a few seconds the gap was gone. Solid machinery where the path had been. The structure still humming behind it.

They waited.

Tinker took one step back.

The machinery moved again. The path reappeared. Exactly as before.

They looked at each other. Jolt tried it once more, just to be certain. Same result.

They stood at the edge and looked at the structure through the gap in the machinery. It kept humming. It didn't seem to care about any of this. It had been out here a long time, doing the same thing the whole time, and it would keep doing it until somebody figured out how to stop it.

"It calls for something that doesn't come," Rivet said. "It's been draining our grid the whole time for nothing. And now that we've found it-" he looked at the closed path "-it won't let us near it." He turned to the others. "We need to shut this down. So how do we get in?"

Five inventors. No instrument. Sixty seconds of clues from a robot that had been face-down in the rocks.

They got to work.