Chapter 562

Because tomorrow is Thursday, which is the fifth day of September, it is the date when the "letter" mentioned before Detective Sparrow's death arrives. After sending off Galina and Difa on Wednesday night, Xia De had been guessing what the content of that letter would be.

With his wild imagination, the guesses became more and more bizarre. In the end, he even thought that maybe it wasn't a letter but a package, and opening it would trigger a steam bomb.

Because he thought about too many things, after falling asleep on Wednesday night, he had a bizarre dream. At the end of the dream, he actually saw Mr. Sparrow Hamilton. The gentleman in the dream didn't mention the task given to Xia De, but blamed Xia De for raising a cat in St. Deran Square, making the house dirty.

"What kind of weird dream is this?"

Xia De woke up suspiciously, and then found that it was only five-thirty.

Staring at the ceiling in the dark, he lay for ten minutes and really had no sleepiness, so he sat up from the bed. With the arrival of autumn, the sunrise time is getting later and later, and the curtains in the bedroom are drawn, so the room is pitch black.

However, probably awakened by Xia De's movement of getting up, the cat curled up beside the pillow opened its eyes alertly, looked at Xia De, and after finding it was him, meowed a few times, and then fell into a deep sleep again.

It is not yet time for this cat to get up.

Because he couldn't sleep, Xia De got up early, changed into clothes he didn't usually wear, and went out directly. But he didn't go far, but sat down beside the fountain statue of a girl holding a water bottle in the center of St. Deran Square, holding some bread crumbs to feed the pigeons.

These pigeons seem to always be here.

His appearance was very suspicious, and even the passing patrol police looked at him twice. But as time came to six o'clock, there were gradually other people in St. Deran Square, and he didn't look so conspicuous anymore.

Xia De wanted to see who exactly was delivering the letter to St. Deran Square.

Starting at six-thirty, the postman delivering letters and the deliveryman from the milk company arrived one after another. Letters and newspapers were sent into the foyer through the delivery slot under the door, while milk and goat milk were placed in the milk box on the right side of the door.

Xia De had not moved, which resulted in Mia, who woke up at six-thirty sharp, seeing Xia De from the bedroom window and staring at him with bright eyes from the windowsill.

Xia De waited until seven o'clock, and seeing no one else staying at his door, he sprinkled all the remaining bread crumbs in his hand to the pigeons.

After standing up, the pigeons flapped their wings and passed over Xia De's head. Xia De walked to his door and took out the milk box key to unlock it. After taking the glass milk bottle and opening the door, he saw the newspaper he had ordered on the foot mat, as well as two letters with stamps.

"Could it be that this kind of letter is sent through the post office? Is it so bold?"

Xia De thought suspiciously.

He first made breakfast for himself and the cat, and only then opened the letters at the dining table.

Of the two letters, one was an official letter from the Association of Prophets, inviting Xia De to attend the opening ceremony of the "1853 Great City Player Luo De Card Tournament" held at the Association of Prophets on Silver Cross Avenue tomorrow.

Since Xia De took other people's money as a special guest player, he would of course be there tomorrow.

And the other letter came from a gentleman named Greil Igor. The return address was written as a street in the north of the city, but there was no more specific house number, so it should have been delivered directly to the mailbox at the intersection.

"I have a wonderful premonition that this is the one."

Xia De thought in his heart, feeling a bit excited:

"This is a puzzle that has lasted for more than two months, what will it be?"

Opening the envelope, there was only one folded piece of letter paper inside. The back of the letter paper had no words, and the front was neatly written in Delarion language with blue-black ink. But there was only a short line, not even a greeting or a signature—

【Still the same as before.】

"Really impolite, but what does this mean?"

Xia De was very curious.

【Aren't you going to burn this letter?】

She asked softly in his ear.

"Burning the letter and figuring out the content of this letter do not conflict. This is a puzzle that has lasted for two months."

Xia De responded, holding the letter against the sunlight from the window, but there was no reaction. Seeing Mia leaning over curiously, he handed the letter paper to it again.

It sniffed, and then turned back to its breakfast.

"Really interesting."

Xia De concluded that this letter was not that simple, and today's idleness and strong curiosity did not allow him to give up now.

"I just want to know what this is, not wanting to get involved in Detective Sparrow's troublesome affairs."

So after breakfast, Xia De took this letter to the Church of Dawn and found Priest Ao Gu Si in the church. The priest had already received the specific departure time and planned to discuss his long-distance travel plan with everyone on Saturday.

Seeing Xia De coming, he even greeted him to help think about what else he needed to bring. The climate in the southeast of the kingdom and Tobesk were completely different.

"I came to ask if there is any way to make invisible words visible."

Xia De shook the letter in his hand:

"It might be written with special ink, but I don't know exactly what it is."

If it was really what Xia De thought, then Detective Sparrow should have destroyed the potion to make the ink visible long ago. A dying spy had no reason to leave behind anything that could expose his identity.

"A Ringed Sorcerer's letter? Used strange arts to hide the words?"

Priest Ao Gu Si asked.

"No, just an ordinary person's letter, I guess it's special ink."

"Ordinary people are easy to handle."

The priest didn't even take Xia De to his potion workshop, but found a small glass bottle covered in dust in his room in the church. The liquid in the bottle was black and looked exceptionally thick:

"Try this, revealing potion, generally used to detect objects that can be touched but cannot be observed by the naked eye and other methods. This bottle of mine has expired, but it is still very useful for ink. This is not revealing through chemical reactions, but conceptually making things that 'exist but cannot be seen' visible."

Invisible ink is also ink, there must be traces of ink on the paper.

This kind of potion with a simple formula requires specific rituals to exert its effect, and using it to crack secret letters is like using a steam bomb to bomb a mosquito.

Priest Ao Gu Si did not bring the ritual materials into the church, so he let Xia De take the revealing potion home to do it himself.

Xia De immediately proposed that he wanted to pay for this potion, but the old priest waved his hand and let him leave directly:

"It might be worth some money if it hadn't expired, but this bottle has already expired, so just treat it as helping me throw away trash. I always think about throwing it away one day, but I'm always too lazy to get it out from under the bed."

Saying goodbye to the priest, Xia De first went to Old John's Pawnshop and spent 3 shillings and 9 pence to buy ritual materials. Because the price was cheap, Xia De didn't even bargain, which made Old John, who was looking forward to him saying "cane," very disappointed:

"Sometimes I feel that the fun of doing business with you is even greater than the fun of earning those few coins in your pocket."

After returning home, Xia De simply set up the ritual on a blank piece of letter paper, and then put the letter from this morning on it. After pouring the potion given by Priest Ao Gu Si, there was no reaction on the letter paper.

"Um... guessed wrong?"

Xia De, who was in front of the desk, thought about it, took down the letter paper with the small line of words, and put the envelope on it. After pouring the potion given by Priest Ao Gu Si again, dense numbers appeared on the inside of the envelope.

"Very good."

A smile of excitement appeared on his face, but these numbers connected together had no meaning at all.

"Sheet music? Doesn't look like it... Code, Detective Sparrow's code..."

Xia De turned to look at the bookshelf and took down the detective's relics 《The Queen and Her Lovers》, 《The Silver Knight》, and 《Western Front Remnants》.

These three novels were the only few novels Detective Sparrow had before his death, and there were many traces of flipping inside. Xia De had once speculated that this was a spy's codebook, and now he finally had a chance to verify it.

"But why didn't he destroy these three books before he died?"

When flipping through the books, he thought suspiciously again, and then realized that compared to strange ink, these three novels were plain and unremarkable. People who suspected his identity would sooner or later notice the books missing from the study even if he destroyed these three books; people who didn't suspect his identity wouldn't care about these three books appearing on the bookshelf.

"But how to compare those numbers with these three books..."

Looking at the things on the desk, Xia De fell into deep thought.

The numbers revealed on the envelope were not completely continuous. A clear space would appear every few numbers. And taking the front and back of the space as a group, each group was eight numbers.

"These three books are all three-digit page numbers, and the binding specifications are similar. Judging from the number of digits on the envelope, it is impossible for each group of numbers to correspond to a letter. It should correspond to a word, and the number of lines and columns of words on each page are only two digits. That is to say, if you want to point to a word on a certain page, certain line, and certain column, you only need 3+2+2=7 digits. But now each group has eight digits, what does the extra one point to..."

Mia jumped from the ground onto Xia De's lap, and then from Xia De's lap onto the desk. Seeing three books on the table, it immediately stretched out its claws, and then was held down by Xia De.

"Could it point to a book? The codebook is not composed of one book, but multiple books?"

He compared all the numbers on the envelope again and found that the last digit of each group was "1", "2", or "3", and no other numbers appeared.

"It's very simple this way, the last digit of each group refers to the book."

Xia De smiled.

But this created a new problem. Even if such a guess was correct, he didn't know the book numbering corresponding to the three novels.

"But it doesn't matter, you can try one by one. First translate the first 10 groups of numbers. If they can be connected into a meaningful sentence, it means my idea is correct."

【Three digits correspond to three books, you have to guess many times.】

The voice came from his ear.

"It doesn't matter, just six possibilities of arrangement."

Xia De thought in his heart, took the notebook, and began to record the letters corresponding to the numbers. Ten groups of numbers and ten words, and although there were six possibilities of arrangement, in fact, each group of numbers only needed to be looked up three times.