A big question had been whether hydrogen was at all a sane option for the new airship's balloon. The answer was that the System did acknowledge the balloon as qualifying for the Blastproof feat, apparently because of the system of ropes and vents and heaters linked to it. When Vonn intuitively studied the thing through Engineer senses it seemed like a borderline device, something that the System hadn't fully decided how to classify. But hydrogen presented another problem besides being what Selen called "explodium": it leaked through materials like cloth, and she didn't have a quick and trustworthy solution. She noted that some historical balloons used one chamber of hydrogen or helium (which they couldn't get) and one of hot air, so that was a possibility for later. For now they just used air and had the advantage of basically infinite heating fuel.

He stenciled a name on the side. Liberty Bell, this time. An actual bell chimed on the bow.

By all the gods and Dragons, this one was expensive. A bunch of people had worked hard to harvest the crystals for this thing. He could only justify it as a serious project of national value, a refinement of Birb's first airboat to give it more cargo room and safety. Still a poor cousin to the airplane in terms of speed, but most possible crashes would be gentle. Crucially, it also didn't require a constant Stamina drain to handle its controls.

And "expensive" was relative. This wouldn't be a typical family vehicle, but a business could use one.

Vonn was the first one up in it, balancing and getting a feel for how to scurry around. The flimsy hull swung beneath its gas envelope. He'd begun wearing two of the emergency slowfall bracelets, one on each glove, keeping one disabled as a backup. Up here he still felt queasy but was getting used to the vertigo. Thirty feet up on a set of guide ropes, in a gentle eastward breeze.

He called down through a wooden cone. "Release!"

The ground team began slackening the ropes, letting the ship make a wobbling ascent. Vonn bristled and hung on. His teeth gritted as he tried to gauge when he'd reached vertical balance. At some point he'd reach an air pressure too thin to support the boat. Up and up he went, to the limit of the two hundred feet of rope. He vented air from above and got down to within that height. This world had slightly higher air pressure than Earth combined with a bit less gravity, a possibly magical combination. As a result, pressure decreased more slowly with height and there was less sharp a flight ceiling for a craft like this. Good for flight overall. But it meant he'd have to pay extra attention to his altitude.

Birb flew up partway so she could shout, "Instruments?"

Vonn checked what few of those he had. There was a pair of tiny levels, in the form of vials with trapped bubbles that could indicate tilt. A compass. They'd tried to make a "pitot tube", a forward-facing tube open in the front and allowing oncoming air to push against a spring. Wasn't reliable yet, though, and the speed gauge they'd added to the propeller engine wouldn't tell him absolute speed. A wind-sock in orange with a white tip was the wind meter.

He took notes, then shouted downward. "Coming down!"

He vented gradually and let Liberty Bell drop, until it could be hauled down again and secured. He hopped to the ground and bowed to the small crowd.

"Are you flying somewhere today?" asked a shopkeeper.

"No way. We need more testing first. But does anyone want a ride with my fellow pilots?"

A skinny young Centaur became the first of her kind to fly on an airship. She was up there with Birb to test the weight limit, crouching on improvised board seating. She clutched the ropes and rails so hard Birb worried she'd break something. They only got around fifty feet up and the she barely peeked over the side before letting out a squeak and huddling on the wicker floor, eyes shut. So that didn't last long. Successful test, though.

#

Vonn got as far ahead as he could on pressure vessels. Then he and Tazo went up to make a real flight. Northeast across the Starry River to Silvermire, on a day of moderate eastward wind. Each of them had a loose harness of rope, just in case, and they'd practiced falling from a much lower height.

Up in the sky, Tazo held the boat tightly and shut her eyes, feeling the cold breeze in her fur. "Starting to really go somewhere, as more than an emergency."

"Yeah. The tricky thing will be to do it routinely. To be up here in an airship and wave to more of them passing us."

She looked around at the river below. "What will your embarrassing story for Fool's Day be, this year? You've managed to not get dunked in the river again."

"Don't jinx it!"

She laughed, glanced around once more, than busied herself with the engine again. "Takes hard work to make it look easy."

It took over an hour to reach their lord's main village and they worried about the wind for most of it. When they reached the swamp there were tiny figures below, staring and pointing. Vonn grinned and waved, then got back to work. "Checklist!"

"It fell overboard," Tazo reminded him.

"Ah, right. Engine to half."

"Check!"

"Begin venting, check!"

They made not for Silvermire itself but for the quarry village just north of there, where there was more clear, level ground. The wind began to fight them and they dropped fast enough to make their stomachs lurch before recovering. But they dropped their rope and shouted at the guy who decided to yank it too hard until he cooperated. As they got reeled in, he forced himself to stay careful and check everything. The ship wobbled and the gas bag vented faster than he wanted. After a few harrowing final minutes, they were anchored again, and again had a crowd. The villagers here hadn't seen more than an early experiment with a glider plane and an early balloon flight, so this fancier model was a novelty.

"Did you come from the sky?" asked a kid.

"From Shieldpoint!" said Tazo.