Chapter 389: The Third Passage

The shutters were drawn against the glare when Ren reached Shadewell’s clothing counter. He collected the cloak, hood and hand covers, fastened them over his own gear, and followed the covered route toward the garden. At each gap he checked his fastenings before crossing the bright paving.

Joss waited inside the keepers’ entrance with a lamp, a bundle of cloth strips and a folded sketch.

"Tobin’s checked the section," he said. "Look at this before we go down."

He spread the sketch against the stair wall and raised the lamp.

"The first passage serves this opening. The second goes deeper before it divides. One branch serves the opening you worked on before. The other continues to a third."

"So both those openings get their air through here."

Ren put a finger just above the fork. Joss nodded.

"Watch that stretch as well as the outlets. The longer branch can still be responding after the nearer one settles."

Ren copied the fork into his notebook, leaving room beneath the third outlet. Joss waited until he had labeled the mouths before folding his own sheet.

Below, Tobin stood beside the feed slide in a sound stretch of gallery, clear of the damaged branch’s relief path. He showed Ren the settings on his card.

"These are the marks we’ll use. The beds can take these changes while we tend the air. Nothing beyond them."

Joss hung one strip at each outlet. The first was near the stair, the second farther along the wall, and the third beyond it. At a low inspection recess, he lifted a glazed cover and tied the fourth strip just upstream of the fork. He closed the cover, checked its seating, then waited for the flow to settle.

Ren crouched to look through it. From there he could see the strip lifting into the stretch that fed both branches.

The three outlet strips moved at different angles. The first lifted farthest from the wall; the third stirred in a weaker current. Tobin checked them with Joss before returning to the slide.

"What have you practiced since we last worked together?" Joss asked.

"A shelter on the coast. Low inlet, high outlet, a working corner at the back. Drawing harder at the outlet pulled the air straight past the corner. I had to ease it and guide some of the current along the back wall."

"And keep its route out clear."

"Yes."

Joss tapped the inspection cover.

"You’ll need to follow the whole exchange here, too. But you can’t see the stretch beyond this fork. Check what’s feeding it before deciding what the far outlet needs."

Tobin moved the slide down one mark. For a while the strips scarcely changed. Then the first eased, and the second began to fall.

Joss brought his working into the passages. Ren followed him strengthening the flow through the common stretch before the fork, keeping the first passage’s current moving as he did it. The fourth strip lifted farther. The second outlet recovered first; the third continued weakening before it began to rise.

Joss eased his working as the branches settled.

"See how long that one kept changing?"

Ren nodded. He had been watching the third strip.

Tobin restored the normal feed. Joss withdrew, checked the outlets once more, and stepped aside.

"Yours."

— • —

Ren brought Air to the openings and the stretch visible through the inspection cover. He waited until Tobin looked over, then nodded.

The slide moved down.

At first, the lining’s stored heat kept the strips near their earlier positions. The first outlet eased before the second. Ren maintained its current, then strengthened the flow into the common passage upstream of the fork as the second strip dropped.

The strip inside the recess lifted. The second outlet had not recovered yet, and the third was beginning to sag.

Ren gave the far mouth a small additional draw. It had not stopped flowing, but he wanted to keep it from weakening further while the rest caught up.

The third strip rose. Along the wall, the second began recovering too.

Then the third snapped outward, well beyond its earlier angle. The second strip faltered again.

Tobin still had his hand beside the slide. It hadn’t moved from the lower mark; the second outlet’s new drop had followed Ren’s added draw.

"What had you already changed?"

Joss stood beside the stair, watching him.

Ren crouched at the cover. The fourth strip was still lifting farther into the common passage. He had increased the supply to both branches, then added another pull at the far outlet before seeing the full response to the first adjustment. Now the stronger current was arriving there, and his extra draw was taking too much toward the third opening.

He eased that local working. The far strip lowered, and the second began lifting again. Ren kept his upstream adjustment steady until both had settled, watching the first outlet throughout.

’I’d been very quick to make that worse.’

"I thought the third needed help while it caught up," he said.

"It might. But you kept the extra draw after more began reaching it."

"So I watch the junction first?"

"Here, yes. You’ve already changed what feeds that outlet. Check what your change is doing before adding another."

Joss crouched beside him and pointed through the cover.

"That strip was moving before the third rose. You had something to go on."

Ren looked from it to the far mouth. He had seen the movement, then abandoned it to watch the strip that seemed to need him most.

On the next change, Tobin raised the feed to a permitted mark above normal. Ren kept the first passage flowing and watched the current strengthen before the fork. The second outlet lifted while the third still lagged.

He gave the far mouth less help this time. As its current began strengthening, he reduced that addition instead of waiting for the strip to snap outward. The second opening kept its flow.

"Leave room for what’s still changing," Joss said.

They repeated the exercise with Tobin moving between the marked settings. Ren sometimes needed a small adjustment at the far mouth and sometimes none. He kept returning to the junction strip rather than treating each outlet’s movement as a separate problem.

During a lower feed setting, the second and third strips settled closer to the wall than they had at normal. He glanced at Joss.

"Those are within what the beds need," Joss said. "Keep watching."

Ren held them there without trying to restore the old angles.

Before the final test, Ren waited by the recess while Tobin showed Joss two marks and their order on the card. Joss read them, checked the outlets, and came back to Ren.

"Two changes. I’ll watch; you make the adjustments."

Ren stood where he could reach the inspection recess in two steps and still see all three mouths. Tobin turned to the control.

The first outlet weakened. Ren maintained its current while waiting for the other passages to respond. When the second began dropping, he increased the flow before the fork and crouched to check the fourth strip.

The third eased toward the wall. He watched it, then the junction, where his adjustment was already showing. The far current remained weak, but it was still moving. He left the mouth alone.

The second recovered. The third took longer, lifting gradually as the changed supply reached it. Ren eased his upstream working as both settled, keeping enough current moving through the first passage.

Tobin held that setting. He checked the lining while Ren watched the strips continue moving in their steadier currents.

The second feed change came after the section had spent a while at the lower setting. This time the strip before the fork took longer to lift, and its swing was smaller.

On the earlier increase, more had been reaching the fork by this point. Ren kept his working steady instead of easing it according to that earlier response. The lining had spent longer at the lower feed this time; he watched what was reaching the branches now.

He maintained the exchange until the fourth strip began lifting farther. Then he reduced his upstream contribution with it. The second outlet rose, followed later by the third. A small adjustment at the far mouth kept its current from drawing too much out of the nearer branch as it strengthened.

He remained by the recess until the strips settled.

Joss walked along the outlets. Tobin checked the lining again and returned to the slide.

"Both changes," Joss said. "You kept them within the section’s limits."

Ren straightened, resting a hand against his knee. He had spent most of the lesson folded beneath that cover.

— • —

Tobin restored the normal feed.

"Ease yours out," Joss said. "I’ll take over."

Ren withdrew in stages while Joss’s tending replaced his contribution. He could follow the working between the nearby openings; farther into the grown passages, he had to watch the results in the strips.

Once Ren had released the last of his hold, Joss checked each outlet and looked through the closed inspection cover. Tobin went along the row to check the returning supply.

"All out?" Joss asked.

"Yes."

They waited until Tobin finished his checks. The four strips continued moving under Joss’s tending, and Ren stepped away from the recess.

Tobin recorded the settings and their order on his card.

"I’ve given Maren a window for the cooling section," he told Ren. "See her before you leave."

She had the sheet waiting in the garden office.

"It’s a checked section on the other branch," she said. "The feed has been reduced ahead of an inspection. Tobin can take you through the lining’s heat release while it cools. He’ll decide what you can work on after checking it that morning."

She pointed out the window.

"Be at the entrance for the start. Once the section has cooled past what he wants to show you, we’ll have to arrange another."

Ren compared it with the transport connections on his slate. One departure left time for the port and the covered walk, with a return service after the session. He showed Maren the arrival.

"That fits," she said.

He booked it and sent her the confirmation.

"Lenna can make time for you as well," Maren added. "I’ll send her window once it’s settled."

"Thank you."

He put the appointment sheet with his notes before fastening his cloak for the walk back. His harness stayed clear beneath the issued layers. At the bright gap beside the water counter, he followed the covered detour with the people ahead of him.

At the port he returned the cloak, hood and hand covers, then confirmed his connection home. He found a seat away from the boarding queue and asked the System privately for the result.

[AIR: 10.8% → 11.4%.]

Ren closed the panel and opened his notes. Beside the fork on his sketch, he marked the position of the fourth strip. Under it he recorded the correction he had made before adding the unnecessary draw at the third mouth.

He sent Lyra his arrival details with a message.

Finished at the garden. Three passages this time. I spent most of it crouched under an inspection hatch. I’ll tell you over tea.

Then he put the slate away and took out Maren’s sheet. He checked the departure against the window once more before folding it into his notes. The lining was already cooling.