After the submarine inspection, Oskar returned to Potsdam—back to his family, and back to the one place in the palace where titles mattered less than sweat.
The palace gym was alive.
Not just with princes and officers, but with the whole household: guards in sleeveless training shirts, maids in modest sweatpants and hooded tops, servants stretching and laughing between sets, even a few older courtiers pretending they were "only observing" while secretly lifting.
It was a strange workplace benefit for 1909—almost scandalously modern—but it worked. Healthier bodies. Fewer sick days. Stronger guards. Straighter backs. And, most importantly, a palace full of people who no longer froze in winter and no longer lived like fragile porcelain.
At the far end of the hall, a fenced-off children's area had been built—part nursery, part miniature training yard. Inside it, Oskar's eight children and Karl and Heddy's little ones swarmed like cheerful invaders, "lifting" bright, hollow practice weights made of molded material and painted wood.
Durin, already three and proud of it, treated the tiny gym like a battlefield. He grunted loudly, copied the adults, and tried to outdo everyone—including Imperiel, who stood with his chin high like a small commander, correcting the little ones when they wandered off-task.
The babies—too young for any of that—mostly crawled, stared, and occasionally tried to chew the fake weights as if that was also training.
In the center of the real gym, Oskar lifted.
Not elegantly. Not politely.
He lifted like a force of nature.
When he set the bar down, the floor shuddered—just a little—as if the palace itself had learned to brace for him.
Karl was nearby, doing curls with twenty-kilogram dumbbells, sweat darkening his shirt. Between sets he took a long drink from a tall cup and sighed with satisfaction.
The drink looked simple.
It was.
But it had become a phenomenon.
Oskar's "protein shake"—sold at Pump World and now spreading far beyond—had people everywhere whispering as if it were secret chemistry. They drank it believing it might turn them into Oskar, might unlock something superhuman.
It didn't.
It was only good, dense nutrition—eggs, milk, oats, a little cocoa for taste—healthy ingredients blended into something that tasted like a treat while feeding muscle and recovery.
Still, the myth sold faster than the truth ever could, and it was earning Oskar millions of marks daily across Germany and beyond.
Karl finished his sip, wiped his mouth, and then looked over at Oskar.
Oskar was curling two dumbbells that weighed eighty kilograms each.
One in each hand.
Slow, controlled, deliberate—like he was teaching gravity a lesson.
Karl stared for a moment, then his eyes narrowed as memory snapped into place.
"Hey," he called out, "weren't you supposed to meet Mister Gustav Lilienthal today? The aviation man. He wanted to see you. So what are you doing here sweating like a bulldog?"
Oskar paused mid-set.
He sniffed his own armpit with the casual seriousness of a man conducting research, shrugged, and continued curling.
"Hmm?" he said, as if Karl had asked about the weather. "Ah. Yes. That."
He finished the curl, lowered the weight, and immediately lifted again.
"I forgot," he admitted, completely unashamed. "I got swallowed by the Thuringia plans."
Karl blinked. "Thuringia?"
"The hydroelectric plant," Oskar said, still curling. "We need the power for the aluminium works."
Karl stared at him as if he'd said we need it to power the moon.
Oskar kept going, voice calm, eyes distant with calculation.
"Aluminium doesn't come from hope and patriotism," he said. "It comes from electricity. A proper aluminium plant eats power like a small town. It's insane. Beautiful, but insane."
He exhaled through his nose, then added, as if solving the problem required only one sentence:
"Send Lilienthal a telegram. Tell him to come here. If he wants to show results, he can show them in Potsdam."
Karl sighed like a man accepting that this was his life now.
"Fine," he muttered. "I'll do it."
He set down the dumbbells, already grimacing at his own sweat.
"And I'm taking a shower first," he added. "I'm not writing letters smelling like a stable."
Oskar waved a hand in permission—still curling, still building his hundred-count set as if the world could wait until his arms were satisfied.
Karl walked off.
Left alone with the iron, Oskar let his thoughts drift toward the sky.
Gustav Lilienthal was the man steering Oskar's aviation push—the project Oskar stubbornly thought of as the beginning of real flight, not circus tricks.
He had already invested twenty million marks into it.
He had secured the cooperation of the Diesel engine sector, test benches and machine tooling dedicated to aviation powerplants.
And now—finally—it was time to see what all that money had bought.
Every country was experimenting with aircraft, yes.
But Oskar knew the future.
He knew where designs were supposed to go, how engines were supposed to evolve, what mattered and what was a dead end.
And in this world, the Wright brothers were gone—dead in tragedy before their work could mature—leaving a hole in the race that Germany could fill.
Oskar finished another curl and felt that familiar impatience bite.
Submarines were teeth beneath the sea.
Now it was time to see if Germany was learning to grow wings.
---
Later that same day, Gustav Lilienthal was shown into Oskar's office.
The older man moved with an engineer's nervous energy—shoulders slightly forward, hands never quite still, eyes bright in a way that had nothing to do with youth and everything to do with obsession. He held Oskar in almost reverent esteem, even though the Crown Prince was young enough to be his grandchild.
Not merely because Oskar had funded them when others laughed.
But because Oskar spoke about flight the way Otto Lilienthal once had—like a man who could see what the air wanted to become.
"Your Imperial Highness," Lilienthal said, bowing deeply. "Thank you for receiving me on such short notice."
Oskar rose briefly—courteous, not submissive—and gestured to the chair opposite his desk.
"Sit, Mister Lilienthal," he said. "And tell me you have good news."
Lilienthal's face broke open with excitement.
"Yes, Your Highness. We do." He leaned forward as if the words couldn't leave him fast enough. "Our first proper working aircraft has been completed. Yesterday we conducted its first test flight—"
He swallowed, then grinned like a man trying not to shout in a palace.
"—and it was a complete success."
Oskar's fingers stilled on the edge of the desk.
In that small pause, he felt the same sensation he had felt in shipyards: the future pushing its hand through the present.
"Good," Oskar said softly. Then, louder, controlled, "Very good."
Lilienthal nodded rapidly.
"Therefore," he continued, "I have come to invite Your Highness to witness our second test flight."
Oskar's smile sharpened.
"I will be there," he said at once. "Possibly with my family—or at least with Karl, if he can be dragged away from paperwork without screaming."
Lilienthal chuckled, relieved.
Oskar leaned back slightly, already calculating.
A functioning aircraft—however crude by future standards—meant Germany had just taken its first real step into a new dimension of warfare and movement. It wouldn't make Africa "close" overnight. It wouldn't turn planes into passenger transport tomorrow. Engines still had limits, reliability still had limits, the entire discipline still sat on the edge of invention.
But it was a door.
And once opened, doors never closed again.
In his mind, Oskar saw the shape of what would come after: reconnaissance, artillery spotting, fast messengers that could outrun rail. Then stronger engines. Better frames. Lighter structures. The long climb toward true dominance.
He didn't say the most ambitious thoughts aloud.
Not yet.
But they lived behind his eyes all the same.
"When?" Oskar asked, voice steady.
Lilienthal blinked, as if he'd nearly forgotten dates existed.
"In three days, Your Highness," he said quickly. "We intend to conduct the second flight once the weather window is favorable."
Oskar nodded once.
"Then I will be there in three days," he said. "Send the details—location, time, wind conditions, and your safety arrangements. I want no improvisation. Not with this."
Lilienthal's grin returned, boyish and proud.
"Yes, Your Highness," he said. "You will have everything."
Oskar held his gaze a moment longer, and in that silence Lilienthal seemed to understand that this was more than curiosity.
This was investment.
This was hunger.
This was the Crown Prince looking at the sky the way other men looked at empires.
"Good," Oskar said again, and this time the word carried weight.
"Let's see if Germany can learn to fly."