The Ten Skies was the last ship in the long line waiting to pass through the portal that Ingrid had created over central Taisia. She flew her fighter slowly with full flaps and landing gear out, bleeding airspeed before turning to land on the deck. It was a smooth and unremarkable landing. As she descended the ladder to the deck, Reese was waiting for her at the bottom, wearing the black and white uniform of a Lieutenant.

"That was such a beautiful landing!" Reese said. "I hope I can learn to fly like that someday."

"Ivan is a good teacher," Ingrid said. "And I've had a lot of practice."

"Thank you again for your recommendation that I be brought in as an officer. This means so much that I will get to fly in these beautiful machines."

"You trained to be a Matron. That is a lot like being a noblewoman in our world," Ingrid said. "Speaking of the other side..."

Ingrid looked up. The purple-gray portal loomed over the bow of the airship directly in front of the Ten Skies. She did not get a very good look inside when she did her quick loop to claim the keystones, however she did notice that the ground and the sky were both uniformly reddish. The inside of the portal was deeply confusing and she put it out of her mind while flying, instead focusing on her task.

She walked to the bow of her own ship and waited as it slowly crept towards the portal.

"I've never seen this Plane," Reese said.

"Which ones have you seen?" Ingrid asked.

"The Golden Tower in the Plane of Light, the little planets of the Plane of Heaven, the Queen's Prison in the Plane of Darkness, and of course the mazed oceans of the Plane of Water."

"This will be a surprise for both of us then."

Ingrid did not know what to expect inside the portal, but what actually awaited her was so completely alien that her brain simply shut down for a few moments as she gaped at the scene. It was like some artist, who thought he was clever, decided to paint a scene with a heavily distorted perspective, as an inside joke with other artists. Finally her eyes and her mind adjusted and she understood what she was seeing.

The world was completely inside-out.

Perhaps, she thought, this world just had a different shape than her own world. A glance around in each direction confirmed this shape. It was a cylinder. A massive, world-sized cylinder, and they were inside it, not too far from the inner surface. At the far end, a dim grayish sky could be seen through the circular hole at the end of the cylinder, filled with the oily, multi-hued light of sparse nebulae. One section of a purple-gray moon filled part of that hole.

The inside of the world-sized cylinder was completely covered in reddish mountains with veins of yellow, white, black, and even tiny bits of blue or green, as if a painter had dragged a paintbrush across the mountains leaving streaks of colors. These mountains were cut by great rivers of silvery, molten metal, pooling into lakes and oceans that steamed, creating great clouds, vortexes, tornadoes, hurricanes...

And then there were the giants. At least three miles tall, the mercurial humanoids perfectly reflected their surroundings like a mirror, with a tinge of oily chrome. They roamed about, extremely slowly, making rapid but infrequent movements and then standing perfectly still for some reason. They could be seen as bright, silvery specks all across the inner rusty lining of the cylinder.

Perhaps even more bizarre than these behemoths was the inverted pyramids of metal in the sky. The flat surface on top of those inverted pyramids was visible at some angles, and Ingrid could clearly see the skylines of cities. She reasoned those cities must be where the masked people lived.

Taken from Royal Road, this narrative should be reported if found on Amazon.

"Urgent message for Lady Ghost!" a soldier said as he rushed up to her on the bow of the airship. "I mean, Princess Ingrid! The Captain, I mean the Admiral, requests your presence at once."

"Carry on," Ingrid said as she turned towards the command deck.

"I better get back to my duties," Reese said. "The maintenance crew says I need to be able to fix my little airplane using Metal Elementals."

Elizabeth was waiting for her in the map room, looking over reports. A handful of other men in Order uniforms stood around her. Vaska stood at the porthole in the back of the room.

"Ingrid, when you closed the first portal, at about what altitude was the bottom keystone?" Elizabeth asked.

"Maybe, between fifteen and twenty thousand feet," Ingrid replied.

"That is consistent with our predictions, Admiral," one man said. Ingrid recognized him as the new Captain of the Fleet, who gave orders on the Ten Skies now that Elizabeth was the Admiral. He continued: "The giants are at least fifteen thousand feet tall, and they appear to move chaotically."

"It looks like they are moving slow enough," Ingrid said.

The man shook his head. "Unfortunately that is not the case. We have high-magnification telescopes and we have spotted giants elsewhere in the cylinder that move very quickly. They sprint about, flailing their arms as they go, and then return to the slow motions they exhibit normally."

"The service ceiling of this airship is just over eight thousand feet when stationary and all propellers used for upward lift," Elizabeth said. "In practice the safe operating ceiling is about six thousand feet. If one of those things starts sprinting at us, it could rip one of our airships in half in an instant. Maybe even the entire fleet."

"Presumably the Ayaruans knew this as well," the Captain of the Fleet said. "That is why they sent that bomber instead of airships. The bomber could fly above the heads of the giants with an escort. It might also explain why the portal opened in such a strange location, far away from nearby targets. They might have been weary of nearby giants who happened to be roaming near the target."

"Thank you for your answer Ingrid," Elizabeth said. "Send the order out to the other airship. Pull out immediately, it is not safe here at this altitude."

"Such a strange place," Vaska said as she approached the table. Elizabeth and the men shuffled out of the room, leaving Vaska and Ingrid alone.

"How so?" Ingrid asked.

Vaska pointed down to a drawing of a cylinder with some calculations winding down the page. "I calculated the gravity on the inside surface of a cylinder this size if it was rotating. Specifically, how fast it would need to be rotating to create gravity equal to our world. Of course, this was pointless because the cylinder is not rotating at all."

"How do you know that?"

"The moon is stationary, as are those nebula clouds. Either the entire universe is slowly rotating with this cylinder, or it is stationary as well. The world outside the portal is also stationary, so I am inclined to believe the latter."

"Why would that be important?"

"Because centrifugal rotation creates gravity of different strengths at different altitudes for fixed objects. Our airships, I do not know how gravity would behave for us. Either way, gravity here appears to be uniform and therefore defies the laws of physics. Elizabeth's service ceilings are still accurate. The Ayaruans likely discovered this as well."

Ingrid scratched her head, still uncertain as to the meaning of Vaska's rambling. She assumed that another engineer would find her observations important.

"I think we need to fly to the other portal as soon as possible," Ingrid said. "Like we did for the Plane of Water. We can cover the four hundred knots in an hour with our fighters. We do not want the enemy to close the portal on their own. We would lose track of those keystones."

Alarms on the airship began to sound, amplified by Wind Elementals. Ingrid covered her ears.

"I think it's a trap!" Vaska yelled. She walked up close to Ingrid to speak in her ear directly, but still needed to almost shout. "Closing the portal to the Plane of Wind! Just a few feet from Jelka airspace! Is not something! That we will likely be able to repeat!"

The entire airship jolted, almost knocking them both on the ground. Then it reversed direction, drifting backwards towards the portal once more. The alarms stopped.

"So what can we do?" Ingrid asked. She still spoke loudly because her ears rang.

"I think we need a conventional invasion of Ayaru," Vaska said. "While that is happening, we send a squadron of fighters through the Plane of Metal far above the giants here and close the portal from this side while they are distracted."

"Are we ready for that?" Ingrid asked.

"I will speak with Rudolf. If that doesn't work, I will speak with my father. And if that doesn't work, I may need to tap other resources."