Page 36 of Daikon

“The Americans probably think they discovered it,” said Major Kishi. “But we’ve known about it for twenty years.”

“Now, the air currents over the Philippine Sea,” continued Yonetsu, pointing to the lower left side of the map.

“This was peripheral to our research. But we did determine that the general airflow at high altitude here is in a northerly direction. So a plane flying south from Japan—to Manila, for example—could be expected to encounter a headwind. Possibly a strong headwind. A headwind on the outward journey and a tailwind on the way back.”

Colonel Sagara was studying the map. The lines indicating airflow sweeping up from the Philippine Sea to Japan merged with a much larger mass of lines extending all the way across the Pacific. They formed what looked like a vast river of air flowing from Japan to the United States.

He traced his hand along the lines. “These are the air currents you used to carry your balloon bombs across the Pacific?”

Yonetsu nodded. “Yes, Colonel.”

Sagara’s gaze returned to the Philippine Sea.

He was drawn back to the lines moving across the Pacific. Project Fu-Go may have been a costly failure, but it had been bold.

“They always move in this direction?” he asked. “East to west?”

Another nod from Yonetsu. “Yes, always east to west. At high altitude the air currents are quite predictable across the Pacific.”

High-altitude air currents blowing across the Pacific Ocean. East to west.

An idea began to form in Sagara’s mind. He placed his hands on the table and leaned over the map, tracing the lines with his eyes.

High-altitude air currents blowing east to west. Always east to west. From Japan to the United States.

The idea came into focus.

A powerful tailwind…

Sagara looked up sharply. “What altitude are you talking about?”

“It varies,” replied Yonetsu. “But approximately from 8,000 to 12,000 meters. For the balloons, we considered 10,000 meters ideal. If they rose much higher than that, they could overexpand in the heat of the sun and explode. Too low and they drop out of the current.”

“That was the greatest challenge,” said Kishi. “Automatically adjusting the ballast. During the day, when it’s hot—”

“And the velocity of these currents,” interrupted Sagara. He tapped the inscription on the onionskin overlay. “What do you mean by ‘high speed’?”

“Again, it varies,” said Yonetsu. “They’re highest in winter—”

“Forget about the winter. Tell me about now.”

Yonestu produced another paper, columns of numbers, and laid it beside the map. “Well, at an altitude of 10,000 meters, air current speeds of around 200 kilometers per hour could be expected.”

“Blowing from Japan all the way to the United States,” said Sagara.

“Exactly. Given ideal conditions, we estimated that a balloon could reach the west coast of the United States in as little as thirty hours. That would be in winter, of course, when the currents are strongest. The average traverse time would be perhaps double that.”

“And from Tokyo to here.” Sagara stabbed the map with his finger. “How far?”

“About 8,500 kilometers,” said Major Kishi. “If you could plot the most direct course across the Pacific, following the curvature of the Earth. But in a balloon floating freely, it’s actually longer. More than 9,000 kilometers.”

Sagara brought his hand down on the table with a triumphant slap, making the men jump.

But if it was a plane!

He stopped himself from blurting it out. He removed a paper from his pocket. On it were written the specifications for the Renzan bomber, which he had previously checked. Service ceiling: 10,200 meters. Cruising speed: 370 kilometers per hour. Range for a one-way mission: 7,500 kilometers.

He added 200 to the Renzan’s speed: 570 kilometers per hour! He snatched up a pencil from the worktable to do the calculation, but somehow he couldn’t.

“What is 8,500 divided by 570?” he snapped, annoyed by his brain’s unaccountable slowness.

Major Kishi reached for his pen. Before he could uncap it, Yonetsu said, “Just under fifteen.”

A smile spread across Colonel Sagara’s face.

The Renzan was capable of a fifteen-hour flight.

It could be done.

The dreaded summons from General Anami, the Minister of War, was awaiting Colonel Sagara when he returned to his office. He took two Philopon tablets to brace himself before venturing downstairs.

Anami did not look up when Sagara entered.

The colonel stood at attention before his desk, ignored, as the door closed behind him and the War Minister continued to write.

Anami was in shirtsleeves, the strength he had developed from decades of archery practice visible in his shoulders and forearms. The bristles on his close-cropped head were graying.

His shirt collar, Sagara noted, was frayed.

“I had quite an unpleasant call from the Navy Chief of Staff,” said Anami at last, still without looking up. “Because of you. I was obliged to apologize on behalf of the Imperial Army. But he still wants you broken.”

He finished writing and looked up at Colonel Sagara at last. Sagara inclined his head to show his contrition. He knew his Hikari mission had caused trouble. But to hear General Anami speak of it extending to the highest echelons—that was unsettling. Thankfully the Philopon was doing its work.

“In normal times,” Anami continued, “you’d be facing a court-martial now. Don’t you think?”

Sagara didn’t respond. Anami let the threat hang in the air.

“But these aren’t normal times,” the general continued. “So consider yourself reprimanded. And you will write a letter of apology, addressed to the Navy Chief of Staff. Now sit down.”

Sagara bowed deeply and took a seat on the hard chair facing the general’s desk. Anami leaned back, rubbing his neck as he took a deep breath.

“All right,” he continued, his tone a few degrees warmer.

“Colonel Takeshita has informed me about this uranium bomb you’ve recovered, and about your plans to use it against Tinian Island.

To destroy the Special Task Planes. I told him I found the whole thing doubtful.

A salvaged weapon, one we know almost nothing about…

How confident are you that it could actually work? ”

“Very confident, General,” Sagara replied, struggling to contain his excitement.

“The weapon is extremely simple, nothing more than a gun firing one piece of uranium into another. If we fire it manually, all risk is removed. Detonation is certain. And we already know the uranium is highly reactive, because there was a mishap in handling it at Hikari. The reactive process was accidentally initiated, very briefly. It created a flash of light.”

Anami nodded slowly as he digested this. “It still seems unlikely. But you need only one aircraft for this mission?”

“Yes, General. The Renzan bomber at Tama Airfield. It’s just been sitting there, going to waste.

But about the target, General, a better alternative has just presented itself.

A more appropriate target, one that will shake the Americans to their core.

They’ve been firebombing our cities. And now they’ve used this same weapon—I’m sure it’s the same weapon—against Hiroshima.

And now we can do the same. A city for a city.

There are air currents blowing across the Pacific, from Japan to the United States—”

He fell silent. Anami had retrieved a paper from his desk and was holding it out.

“I take it you haven’t heard,” said Anami. “The Americans just used another new-type bomb. Nagasaki was attacked at eleven o’clock this morning.”

Sagara read the terse report, his heart sinking. Three B-29s spotted, flying high. A flash of light. A mushroom-shaped cloud. Radius of immediate total destruction 1.6 kilometers. Fires still burning.

“Forget about alternate targets,” said Anami. “There can be only one target: Tinian Island. If you can do it, I want those Special Task Planes and everything around them destroyed.”

“But General, we can reach the United States. If we use the air currents—”

Anami held up his hand for silence.

“Enough. It’s not just about striking back at the Americans now.

It’s about maintaining our spirit. I don’t need to tell you how delicate the situation is on the Supreme War Council.

Keeping the surrender talk in check has become extremely difficult.

And now this.” He motioned to the Nagasaki report Sagara had placed back on his desk.

“This is only going to embolden the surrender faction. How can I argue that we have to maintain our resolve, that the Army can still defend the country, after news like this? And what if it happens again? If the Americans use another one of these bombs to destroy a third city, perhaps Kyoto…”

Anami wearily shook his head.

“If there is any way to prevent it,” he continued, “we have to do so. So make your target Tinian Island. That’s an order.”

He picked up his pen and returned to work. “You’re dismissed.”

Sagara rose and bowed and turned to leave.

“Oh, and Colonel.”

Sagara turned back.

“The Navy Chief of Staff’s office wants to interview those two men,” said Anami. He consulted a paper and read the names. “Keizo Kan and Petty Officer Ryohei Yagi. To corroborate your story. Make them available, will you?”