Research Institute of Mitsubishi Internal Combustion Engine Manufacturing Co., Ltd., Nagoya, Japan.

"11,000 km, are you sure?" The old man in a white coat asked solemnly.

Beside him, a middle-aged man in his forties, also dressed in white, with round-rimmed glasses, nodded, "Yes, sir, at least 11,000 kilometers!" ”

"When will it be developed?" The old man asked again.

The man with glasses replied: "The engine will take 45 days, and if it is tested with an existing aircraft, it can be completed by the end of February!" ”

"Time can't be shorter?" The old man seemed very anxious.

The man in glasses shook his head, "This is already the fastest time!" ”

The old man lowered his head and thought for a while, "In this case, if this kind of engine is installed on the Type 87 fighter, what is the maximum speed?" ”

The man with glasses seemed to have calculated this situation a long time ago, so he told him without thinking: "It should be above 45) kilometers!" ”

Hearing this number, the old man frowned, "This is not enough, according to the calculations of the military department, the other party's speed is estimated to reach 500 kilometers per hour!" ”

"Sir, it will take at least half a year to design an engine that can exceed the ceiling and speed of the other party!" The man with glasses explained.

The old man lowered his head and thought for a while, "Well, let's do it! Don't worry about labor, materials and funding, plus I'll report to the military department tomorrow! ”

The man in glasses lowered his head, "Please rest assured, sir, we will do our best!" ”

The old man nodded, patted the other party's shoulder with his right hand, "May Zuo Fuji Jun be successful!" ”

After the old man left, the man with glasses transferred to his own design room, although the things they talked about were only on the drawings at this time, but for the Japanese Air Force, which was facing a huge challenge, this was their only hope of saving face in a short time.

At this time, in this research room, in addition to the glasses man, there were a dozen other researchers in white coats, although it was already night. But they're still busy.

"For the sake of the empire, for the sake of honor, I hope you will work hard!" The man with glasses said.

"Hey!" Everyone replied in unison that among these people, some are in their 40s, some are still in their early 20s, some have gone abroad for further study, and some have graduated from university in recent years. One of them, Jiro Tsurigoshi, is a 25-year-old researcher who graduated from Tokyo Imperial University's Department of Aeronautical Engineering a year ago, but who has shown a remarkable talent for aircraft design. However, without the experience of studying at the German Junkers company and the American company Kodes, it is not known whether he would have been able to design a truly first-class fighter.

In addition, there is another seemingly unknown person in this laboratory, his name is Honda Tadayoshi, his surname and name are very ordinary, but his ancestor is the famous Honda Tadakatsu, a retainer of the Tokugawa family. A fierce general second to none. However, with the fall of the Tokugawa shogunate, the descendants of the Honke family gradually sank along with the main family, and it was the "one-day coup" nineteen years ago that reminded people of this illustrious family. However, the failure of the coup d'état also became the swan song of the Tokugawa family in history, including the death of most of the coups in the interior of Tokugawa Izunobu, and the remaining retainers either remained incognito or became Japanese spies specially trained by German intelligence.

Honda Tadayoshi falls into the latter category.

Just one day later, news that Japan had been able to build a new supercharged engine for fighter jets at an altitude of 11,000 kilometers reached Berlin and reached Kaiser Wilhelm III.

It was understood that the time should not be delayed any longer, so an extremely important military council was held in his palace. Spee, Vice Admiral Karl. In addition to Dönitz and Air Brigadier General Hermann Lange, the most important generals of the three German armies have gathered again since the launch of Operation Barbarossa. They didn't come here to discuss anything. Rather, it is to listen to the Kaiser's important edicts.

"After the tireless efforts of the government, intelligence services and experts, the death of the former Kaiser Wilhelm II was finally revealed, with the French behind it all and the Japanese as the instruments of the murder.

Now that France has been duly punished, Japan is illegally invading one peace-loving country after another, who will Australia and New Zealand yesterday be, China today, and tomorrow? Guardians of the German Empire. It's time to punish sin with the sword! ”

Japan, the southern waters of Sagami Bay.

Snow begins to fall in Hokkaido in early winter in December, but in the warm Tokyo Bay and Sagami Bay, the night temperature is still around 5 degrees Celsius. On a starless night, two submarines floated side by side on the microwave sea, and apart from the sound of waves crashing against the hull and the occasional conversation, the surroundings could be said to be silent.

The wind was not strong, and the black vulture cross naval flags on the two submarines were waving silently, although the weather was a little cold, standing on the deck of the ship in a trench coat was still a very pleasant thing for the crew on the submarine. Although the German submarines in service have made great technological progress compared with 20 years ago, and the tonnage has risen from the initial few hundred tons to one or two thousand tons, the number of people on each submarine has also increased, and a submarine may be quite large from the outside, but a considerable part of the space inside the submarine is used to place diesel engines, electric motors, batteries, weapons, sonars, telegraphs and other equipment, and the space for the crew to live and rest is very limited, and the problem of turbid air in sneaking has been greatly improved but has not been completely solved (garbage, dung, diesel engines, etc.), and staying in the water for a long time can still be depressing, so the sun and fresh air on the deck are always the most desirable for the crew during the voyage. Of course, there is also the desire for fresh food, meat, eggs, fruits, vegetables, the opposite sex, etc.

"Beware of the cage chicken ......"

An ensign whispered, but it was too late, and the cage was still slammed on the deck, causing the chickens inside to cluck.

"Shhhhh......h ”

At this time, a crew member with a full beard on his face quipped: "Hey, second lieutenant, do you want to eat roast chicken at night?" ”

In terms of size, their U-915 submarine was about the same size as the U-043 on the right, and the two submarines were connected by several steel cables, through which the cages of chickens and baskets of vegetables and fruits were transported from the U-043 supply submarine. Furthermore.

A thigh-thick oil hose is pumping precious fuel into the submarine, which has been floating at sea for more than three weeks.

"Depending on the situation, we will continue to be on standby here!"

"I'm afraid yes, there is no news yet on when the operation will begin, maybe we will have to wait like this until the end of the 10-week maritime duty cycle!"

"Oh, I'm starting to miss land!"

Private Hendrik Meyer was emerging from the submarine when he heard the captain and deputy talking. Like the two officers and most of his comrades on board, he was a little tired of a life where there was no fighting, no entertainment, and just a silent lurking in the sea every day. Sometimes he even complained that the experts who designed the snorkels for submarines were equipped with this kind of equipment that allowed submarines to pump air from the surface of the sea at periscope depth. This allows German submarines to hover or sneak in the water all day long, instead of constantly floating up to breathe as they used to. Since entering the coast of Japan, they have been out day and night every day, avoiding Japanese patrol ships and merchant ships during the day, and only carefully surfacing at night to carry out reconnaissance activities, this kind of routine is like nocturnal animals such as bats and rats, and what is even more depressing is that they can only operate in the waters of Sagami Bay, which is full of temptation and is still a "forbidden land" at present.

(The first practical snorkel submarine in history was built by Germany in World War II, but in fact the Dutch invented this device in the 30s, and the Germans only acquired the technology from the Dutch after the occupation of the Netherlands)

The poor superior soldier hadn't had time to stretch his waist yet. The second lieutenant who had been talking to the chickens had spotted him. "Hey, Meyer, do me a favor. Send these cages of chickens to the storage closet! ”

"Oh God......" Meier looked at the cage covered in chicken feathers and in some amazement, he liked to eat chickens, but he didn't like to be taken up by this thing to take up his precious ventilation time, as a poor deckgunner and orderly, he had just cleaned the two toilets in the submarine.

Although the internal toilet of the submarine can also be used underwater, it must be very cautious and careful to flush the toilet, otherwise there is a danger of sinking the submarine (there are cases in history), and the smell inside cannot be removed underwater, and the "heavy responsibility" of cleaning the toilet when the submarine floats up every day unfortunately falls on the head of Meyer.

The words of the superior were military orders, and Meier was extremely reluctant. But without complaint, he took the chicken coop and slipped back into the cramped submarine compartment, where the smell had not yet fully recovered. A few minutes later, when he finally finished his mission and returned to the deck, the sea replenishment had ended, but the leisure time did not come, and the sonar man found that there were ships sailing nearby, so the order to dive soon came, and Wall had to return to the bottom cabin in a huff.

This is a mine-laying VX-A mine-laying submarine with torpedo tubes and a 40mm deck gun that can easily take out any Japanese freighter. It was also enough to not fall behind against the Japanese light patrol boats, but only if the command gave the order to fight.

Amid the cackling of chickens, U-915 quickly descended to periscope depth, and not long after, a brightly lit Japanese freighter slowly passed by. Sagami Bay is located in the southern part of Tokyo Bay and close to the open sea, and there are many merchant ships and warships passing through it every day, and the German captains found that these Japanese ships were very vigilant when sailing nearby, and merchant ships, freighters, and warships did not have lights at all when sailing at night, and there were also eye-catching lights on navigation beacons and lighthouses.

At night, the lights clearly reflect the outline of the ship, which undoubtedly tickles the hearts of the German captains who have experienced the blockade of Britain and the United States - this is really a good place for hunting at sea!

About half an hour later, another two- to three-hundred-ton offshore patrol boat passed by in the nearby sea. The German captains were told that the Japanese Navy had developed several sonars with acceptable performance by combining self-development and imitation of German-style equipment, but as far as the information was known, those sonars were only equipped with Japanese light cruisers and destroyers, and most of these ships with strong anti-submarine capabilities were deployed in the waters of the Sea of Japan and near the Tsushima Strait, so the German submarines operating in Sagami Bay, especially near the high seas, were relatively easy to operate, and only breaking into the heavily guarded Tokyo Bay was the goal that the German captains were eager to challenge. However, unlike reconnaissance planes that frequently entered Japan's airspace, the consequences would be serious if a submarine was discovered in Tokyo Bay, so the German high command demanded that submarines operating off the coast of Japan not leave the intended area of activity without permission until they received an order.

Once again, the submarine was silently suspended in the water, leaving only the periscope, snorkel and radio receiving antenna on the surface. Private Meyer had no choice but to clean up the garbage such as chicken feathers and vegetable leaves between the cabin and the aisle, he always felt that his courage and ability should not be buried here, if he had a choice, he would rather brave the rain of bullets and guns to manipulate the deck gun to fight the enemy, in fact, except for routine gun training and exercises, he has not really experienced the experience of fighting with deck guns in battle. As his age of 20 indicates, he failed to catch up with the wars of 1924 against the United States or Britain and Canada in 1925, and two years after joining the German Navy's submarine force, he finally looked forward to another chance at war.

"Captain! Telegraph! It's Telegram! ”

The signal soldier suddenly jumped up from his position with great excitement, because the submarine engine was turned off, and his voice could be heard in every corner of the submarine, and Meier was no exception, and he looked at the command room with the same curiosity as everyone else.

"Sergeant, maintain absolute composure when operating in enemy spheres of influence!" The captain has a serious lesson.

The poor messenger also realized his mistake, but his emotions had been suppressed for too long, and although the volume was lowered, the excitement was still overflowing, "Black blue sky, black blue sky!" ”

The captain exclaimed, "Oh God, it's finally here! ”

At 6 p.m. Berlin time on December 18, 1928, that is, at 2 a.m. Tokyo time on the 19th, a clear code telegram was sent from Berlin, and the "black blue sky" was transmitted to German bases and ships in all corners of the world in a very short time.

Soon, the submarines that received the instructions began to move, and the 29 German XX 1A minelaying submarines lurking in the waters of Sagami Bay quickly moved in the direction of Tokyo Bay.