Before the morning session could even fully conclude, Jin took Elsa to the waiting room. Saki followed along to support them.
"Elsa, are you okay?"
"…Yes."
Elsa’s reaction after seeing her father was anything but positive. She didn't seem to know whether she was happy or terrified to see him again. As she spoke haltingly of her conflicted feelings, Saki nodded in sympathy.
"Yeah, I get it, Elsa. I'm in a similar position, after all. If someone asked me if I wanted to see my grandfather, my answer would be pretty complicated too."
"…Saki-nee."
Anxiety still clouded Elsa’s face. Jin gently placed a hand on her shoulder and whispered to her.
"It’s okay. I’ll never let anything happen that you don’t want. Even Her Majesty has recognized your status. If it comes down to it, I’ll just snatch you away and take you back to Hourai Island."
"…Jin-nii."
"Right now, with that disguise, no one will recognize you. And first thing in the afternoon, I’m going to stun the crowd. Just you watch."
"…Okay."
Hearing Jin’s words, spoken with such absolute confidence, Elsa felt her heart lighten a little.
＊ ＊ ＊
At 1:30 PM, following the lunch break, the second half of the day's events began. The giant golem had vanished at some point, likely withdrawn by its handlers during the recess.
The announcer’s voice rang through the venue.
"Now then, we shall begin the afternoon session! Our first presenter of the afternoon is the Honorary Magi Craftman of the Kingdom of Egerea—Jin Nidou!"
Many in the crowd had seen his mini-golems the previous day and knew of Jin’s skill, and a great wave of applause broke out.
Empress Gerhardt Hilde von Rubies Shouro, Chancellor Jung, Magic Technology Minister Degauss, Third Prince Ernest of the Kingdom of Egerea, Third Princess Lieschen of the Klein Kingdom, and the second-ranked magi craftman of the Celuroa Kingdom, Stearena Beta… everyone was intensely curious about what Jin had brought to show them.
Jin, with Steward and Reiko assisting him, began setting up a device in the center of the plaza. Once ready, he began his explanation.
"I am Jin Nidou. Ladies and gentlemen, this is a bag made from ground spider silk."
At the mention of the "ground spider," cries of surprise rose from several sections of the audience. These were the few who knew it was an extremely rare magical beast.
Steward and Reiko unfolded the bag. As they pulled the edges taut, it appeared massive—nearly forty meters long.
"I will now inject a special gas into this."
He connected a hose from the bag to the magic tool he had been running since yesterday and its attached tank. The bag began to inflate. This magic tool was designed specifically to isolate and collect helium from the air.
"O-Oohhh!?"
"Wh-What is that!?"
Before the eyes of the spectators, the giant bag swelled. It was a long, slender balloon with stabilizing fins at one end.
"Wh-Why is it floating?"
Once the slender balloon had inflated to a certain extent, it gradually began to lift from the ground into the air.
"…An airship…" Elsa murmured softly from the arena.
"Eh, what was that?"
"Do you know what that is, Elsa-san?" Reinhard and Bell asked simultaneously.
"Yes. That is called an airship. Inside the envelope… the bag, there is a gas lighter than air, which makes it float."
While she explained, the airship’s envelope continued to inflate until its shape was clearly defined. A passenger basket was attached directly to the bottom of the envelope, large enough to hold three or four people.
Next, cylindrical components were attached to the basket.
"These are magi-propulsion units. They use wind magic to expel air, utilizing the resulting recoil for thrust."
These were not Magi Jet Engines. Those utilized an original magi-formula Jin had constructed by erasing the recoil-absorption parameters, but these units used more conventional magic.
The principle involved using 'Blower' magic to create wind, which was then channeled through a narrowed cylinder to increase pressure—similar to pursing one's lips to blow a sharp breath. By doing so, the device generated pressure that exceeded the recoil absorbed by the magic, and the resulting difference provided the thrust. While its efficiency was lower than a Magi Jet Engine, it provided more than enough power for this purpose.
Finally, the airship was fully airborne. Jin stopped the helium supply, disconnected the hose, and sealed the inlet using Craft Magic.
"In the unlikely event that a hole opens and the gas leaks out, the airship would be at risk of crashing. Therefore, the envelope is divided into several internal chambers so that the gas cannot all leak out at once."
At the moment, Steward was mooring the airship to a bollard with a rope to keep it from floating away, but it looked ready to soar into the sky the instant it was released.
"Now then, is there anyone who would like to join me for a trip through the sky? Besides myself and my assistant, there is room for one more."
"I will!"
A woman’s voice called out instantly. The onlookers were struck with absolute astonishment.
"…Your Majesty…"
Indeed, the one who had volunteered for the maiden voyage was the Empress of the Shouro Empire.
"Your Majesty! You must not!"
Predictably, she was immediately restrained by her frantic retainers. Even Jin was taken aback; he hadn't expected the sovereign herself to volunteer.
"E-Er, is there anyone else?"
"In that case, I will."
The person who raised their hand this time was a face Jin knew well: Saki Eschenbach.
"Then, please, come this way."
Jin beckoned Saki over. Reinhard, who had missed his chance to volunteer by a split second, looked deeply regretful. He had been so stunned by the Empress’s outburst that his reaction time had suffered.
Saki reached the center of the plaza and gave Jin a mischievous grin.
"Kufufu. I was wondering what you were up to, Jin, but to think you'd actually fly. I'm impressed."
Jin turned back to the audience to offer a final explanation.
"A while ago, an organization called the Unifilar entered a battlefield using vehicles called 'hot air balloons.' In contrast, this is called an 'airship.' It can fly faster and for longer durations than a hot air balloon."
A chorus of impressed voices rose from the crowd, likely from those who had witnessed the balloons before. Jin climbed into the basket, followed by Reiko and Saki. From the arena, Elsa watched with an envious expression alongside Reinhard and Bell.
"Alright, here we go.…Steward, let go."
When Steward released the mooring rope, the airship floated upward, completely severing its connection to the earth.
"Oh, it's floating!"
A roar of excitement went up from the stands. Jin took hold of the control stick and directed the magi-propulsion units downward. The recoil sent the airship climbing rapidly into the sky.
"Oooohhh…"
"A-Amazing!"
"…It’s actually flying…"
Under the watchful eyes of the spectators, the airship danced across the great blue expanse.
"Whoa, Jin, this is incredible! It feels so good up here!"
Saki was in high spirits. It was also Jin's first time riding an airship since arriving in this world. The basket wasn't airtight, and the muscovite windshield was only in the front, allowing them to feel the rush of the air. It was a refreshing sensation.
"Alright, let's move out."
As he engaged the propulsion units, the airship surged forward, driven by the powerful gusts of wind.
"Yes, this is perfect! I never knew looking down at the world could feel this liberating!"
Saki remained high-energy while Jin delegated the finer control of the ship to Reiko. Since Jin didn't know the exact technical specifications of modern airships, many of the details were his own original designs.
To manage altitude, he used a magi-device built into the envelope. Heating the air inside caused it to expand and increase buoyancy, while cooling it decreased the volume and lowered the ship. Though actual airships didn't function this way, Jin’s magi-engineering made it a reality.
"Oooooh, amazing!"
"It's really flying…"
"I wish I could ride that…"
"As do I…"
"It’s quite fast. Perhaps even faster than a carriage?"
"That's our Jin…"
"Ufufu, Jin-kun really is something special."
The spectators looked up at the sky with a mixture of shock, longing, and calculated interest in the vessel's practical applications.