"Master, could you see me just now?" Natalie asked William as she slowly followed the instructions of the map, pulling back the "completely disappear" clothes and poking her head out.

"Ha ha, I couldn't see you, but I can now." William laughed. He let Natalie put on the clothes again, and then tried to locate her with a detector, but it was all in vain.

"That reminds me, however." He said to the others, "Now we can't see each other, so we must work together in Room -Ts. That is to say, keep close together so that we won't get apart."

"But there's one problem: how are we supposed to communicate, if we're going to put on those clothes? Talking? Sending radio messages? Don't think about it -- these clothes can even absorb all sound and electromagnetic waves." Said Photon.

Ranran thought carefully for a moment and then answered him,

"We must write what we want to say. It's the only way."

"Wow, that's a lot of trouble." Aria said somewhat impatiently.

William shook his head helplessly, "But there's no other way. Do you want to be found by detectors in that room?"

In the end, they had to do so.

As they spoke, they climbed several hills and passed the strange forest. An arch of stone appeared in front of them. The vault was so dusty that the dust covered the corners of the stone. The dim stars were like sleepy eyes. Starlight illuminated something that looked like an outline. "I'll go and see," Said William, approaching the vault and gently wiping the dust off the outline with his hand. And sure enough, these were the words:

-Ts

William commanded, "Great, this is it! Put on your clothes. We're going to act." So the party put on the "completely disappear" clothes given to them by the spider robot. In an instant they were all gone into the silence of night.

Without the protection of sphere fighters, they had to be extra careful. The best way to protect themselves was to keep those clothes on until they left the room. As they walked through the vault, they walked breathlessly past each detector overhead. Time seemed to be slowed down so much by an invisible force, and their legs moved as heavily as if they had been filled with heavy metals. Once again William felt a huge stone pressing against him, preventing him from moving quickly. "Never take your clothes off..." That was all that remained in his mind.

They opened a door, passed a detector, descended a spiral staircase, and opened another door. Then they saw the detectors surrounding the room, because they had come to the computer.

Even the others could hear William's heart beating fast, and no one knew why. They touched each other to make sure no one was left behind. William approached the chair in front of the computer like a snail, and slowly placed his body on it. Then, stiffly, his hand pressed the power switch.

The light on the switch button lit up. It was an indescribable color, a mixture of the red of blood, the black of terror, and all sorts of other unrecognizable colors. Everyone's blood was frozen. A devil icon appeared on the screen, but disappeared a few seconds later. Moments later, a mouse pointer with tusks appeared in the center of the screen. Then a page appeared,

Please enter the username and password.

If you want to get the password table, please click the "Get password table" button. After that, you will be tested. If the detectors recognize that you are an illegal user, the weapon system will be triggered.

Get password table

"Keep your clothes on!" William wrote on the bodies of everyone. Then he clicked "Get password table".

Hundreds of red lights flashed all around at once, with some faint sounds at the same time. The party froze to the spot, not daring to make a single sound. Although they would be safe enough if they wore the "completely disappear" clothes, they were not taking any chances. Everyone except William clung to each other like a giant snowball. The snowball sat quietly behind the seat.

After what seemed an eternity, the red lights all went out. Then, a password table was presented to them,

000 NUL 032 Space 064 @ 096 ` 001 SOH 033 ! 065 A 097 a 002 STX 034 " 066 B 098 b 003 ETX 035 # 067 C 099 c 004 EOT 036 $ 068 D 100 d 005 ENQ 037 % 069 E 101 e 006 ACK 038 & 070 F 102 f 007 BEL 039 ' 071 G 103 g 008 BS 040 ( 072 H 104 h 009 TAB 041 ) 073 I 105 i 010 LF 042 * 074 J 106 j 011 VT 043 + 075 K 107 k 012 FF 044 , 076 L 108 l 013 CR 045 - 077 M 109 m 014 SO 046 . 078 N 110 n 015 SI 047 / 079 O 111 o 016 DLE 048 0 080 P 112 p 017 DC1 049 1 081 Q 113 q 018 DC2 050 2 082 R 114 r 019 DC3 051 3 083 S 115 s 020 DC4 052 4 084 T 116 t 021 NAK 053 5 085 U 117 u 022 SYN 054 6 086 V 118 v 023 ETB 055 7 087 W 119 w 024 CAN 056 8 088 X 120 x 025 EM 057 9 089 Y 121 y 026 SUB 058 : 090 Z 122 z 027 ESC 059 ; 091 [ 123 { 028 FS 060 < 092 \ 124 | 029 GS 061 = 093 ] 125 } 030 RS 062 > 094 ^ 126 ~ 031 US 063 ? 095 _ 127 DEL

"Oh? Isn't this the ASCII code table?" William suddenly realized, "The set of rules that seemed complicated turns out to be so simple." He quickly asked the little robot to take a picture and then compared the picture of the username and password. He succeeded in breaking the code,

User name: 23091212090113\2

Password: 05=1303^\2

William quickly typed in the username and password, then pressed the enter key. The ugly "Welcome" stung the eyes of the party. It quickly disappeared and was replaced by a black background, several red-and-black icons, together with a blood-red taskbar. William moved the horrible mouse pointer to the "This PC" icon and opened it. He saw that the column "Devices and drives" had four options, but he didn't know which drive to choose.

"Master, you have not decoded the document address." Photon wrote on his body with the propeller.

"Oh, yes! Why did I forget this!" He soon succeeded in decoding the address,

F:\TopSecrets\DisappearingMaterial\Ingredients\ing.txt

William was overjoyed. Without thinking, he opened the corresponding folders according to address names, finally finding the text document successfully. "However, I need to make sure that this is the very document." He said to himself.

The key words in the window convinced him. "Well, I've found you. I guarantee you, that the next second you'll go from 0s and 1s to 0s." He said fiercely.

However, when he tried to delete the file using the "Delete" function in the menu, he was asked to provide his administrator identity.

You will be tested again. Please be prepared. You have 10 seconds left.

"Freeze!" William wrote on bodies of them all. Then he pressed the button.

The red lights on the wall went on again. Nimble Photon quickly embraced the others, and William seemed frozen. When the red lights went off, William was finally allowed to delete the file. So he pressed the mouse button decisively.

The party was happy secretly seeing the file icon disappear from the screen. However, this was not the end. Alarmed, William checked the recycling bin and emptied it.

"This is the end," He told the others.

"Gosh, I don't want to see this horrible system again. Turn off the computer as quickly as you can!" Aria told William, shaking her leading wheels.

"Yes, no problem." He moved quickly to turn off the computer. At last the light on the button went off, and they were once more plunged into a dreadful darkness and silence.

Yet what made them confused, even freaked out, was that the moment the computer powered off, suddenly from behind them came "Hiss...... Hiss..." and it soon disappeared without a trace.

"What's that sound?" Ranran's mind went blank. She remembered the sound they had heard in the underground tunnel. "These two are very similar!" She thought, feeling cold all over.

"Let's get out of here as soon as we can." William wrote on the bodies of the others. He rose slowly, walked to the door, and opened it. As before, they made their way up the spiral staircase, through the detectors, and finally came out of the stone arch and back onto the ground.

"Oh! It's finally over." Photon couldn't wait to take off his clothes. The others also deactivated their invisibility.

"It's so limiting!" Natalie said, a little crossly, "We're not going to wear it forever, are we?"

"I don't think we will need to wear these clothes for a while." William said, "Yet it's good stuff. It makes us 'completely disappear', so it looks like nothing happened."

Rebecca looked at the next destination on William's computer and said nervously, "I don't want to go here..."

"Well, me neither, but we must." William approached her and shook his head helplessly. Then a sharp wind blew, and the party shivered. And what made them even more frightened was that the wind was mixed with that hissing sound, which stung their nerves like a sharp needle.

"I know you guys are afraid of this sound," William replied calmly. His eyes went to Natalie and Rebecca who were trembling. He said, "I'm frightened too, but there are checkpoints there, so let's go."