William jumped into the hole, and so did the others. Dimly they could see the shadow falling fast below them.

"Stop!" Cried William, but all he heard was the dark shadow's snicker. He sighed helplessly, for he knew that the difference in speed would not change for them, who were all in free fall. That is to say, the longer the time, the greater the distance between the shadow and them.

Photon decided to try his weapons. He tried hard to point the nose of the plane at the shadow in the darkness, and then the cannon on the propeller hub shot wildly out a volley of plasma shells. Still it seemed a mighty force, for the shells that had hit it were burning on its surface, causing painful scream to it. He had the time of his life and used the two 15mm guns above the hood. The bullets whizzed along, and the cries of the shadow became more mournful.

But suddenly a dull "dong" came below. It looked as if the shadow had fallen on something. The strange thing was that it seemed to know the way here, and then vanished in the twinkle of an eye.

"Oh! It hurts!" They fell there, too. William cried, "Damn! He ran away!" He shouted in a rage.

Then they heard the sound of a switch switching on. Instantly it was all lit up. They saw that there were white walls in countless numbers, and that at their feet they had a floor like the concert hall above. What was different was that it was without the smell of the trees and it could generate no electricity. They stood at the entrance and could see the corresponding sign clearly. On the left, there were only solid white walls, while on the right, there was a passage. In the distance there was a maze of walls that formed many passages, but only one of these was leading to the exit.

"Eek? Am I dreaming? Why is there a table all of a sudden?" William could not believe his eyes. He blinked, but the table was there. A few seconds ago, there was nothing in that position.

Then Photon noticed a line on the table,

If you want more tips, tap on me three times or more.

He touched it with his propeller and the words on the table changed,

You are at the entrance to a maze. Unlike the other mazes, its passage can't be directly probed.

Next - >

"Can't be directly probed? What does this mean?" Ranran muttered doubtfully. This time it was Natalie's turn to tap the table.

She and Photon took turns tapping, and succeeded in getting all the hints that followed:

This means that there will be several nodes in the passage that are not directly open. They have been marked green and need your probes.

At the nodes you need to answer a few simple questions about instruments or in other aspects. After that, you can successfully open those nodes.

When you open the last node, a prompt tone will sound. Please note that the exit can only be reached by following the correct instructions!

Good luck!

When the table had displayed the last hint, something fell from above, very like a piece of cloth. The table was gone.

"Let's go. There are no nodes here." Photon said.

They turned a corner, ran forward again, and turned right. "Here!" Cried William, spotting the first node. In the distance, they could see a green light shining from there. Hearing his call, the others turned quickly around the next corner to the left.

Where everyone gathered and looked at that node, there was a question,

Which of the following sounds do you think a good music box should sound like?

A The sound of hammering a solid wooden box B The sound of thawing spring water flowing C The sound made by hitting a large instrument

"It must be B." Natalie said with a confident smile, "A's too muffled and C's too deep."

The green light flickered and disappeared. A section of the wall slowly opened, and the scene ahead was similar.

"Great!" The cheering party moved on. But this time, before they got to the next node, Ranran found a very short score on a wall.

"I'd better write it down." As she spoke, she turned on the computer's camera and filmed it.

Then they went to the node. The question this time was:

Just now, on a certain wall, there was a picture like this:

(The figure is the same as above, so no more insertion here)

Please choose from the following two left - hand scores which is more harmonious with the right - hand score.

a.

b.

"Let me have a look," Said William, looking carefully at the three scores.

After a moment, he pointed decisively at choice A. He explained, "It's just a difference between high and low, but B sounds like A minor. Yet the chord in bar 3 should be si -- #G/bA instead of sol -- G, and if it's B, it's out of tune with the C major right hand score. So I don't question my choice."

"Your choice is always the most accurate!" Natalie jumped excitedly as she saw the wall of the node open.

They continued to probe the passage, and the walls grew more and more complicated as they neared the middle. At a fork in the road they saw three directions, and when they probed each other, they found that the real passage was not so easy to find -- those two blind alleys were so deep that the seeker had to walk a long way before he realized it. They sighed deeply and went back to the fork in the road.

"Come with me, since what you saw don't go anywhere." William led the party on, gingerly probing their way out. Suddenly they saw that the road ahead was blocked by several blocks of ice.

"Huh? How can this be done?" Ranran said.

"Let me see." Photon volunteered and went forward to check. He touched a button on the floor, and a bright black grand piano reached out from under the floor. He looked at the ice blocks again. There were five pieces, and they were labeled with the numbers "16" "30" "44" "59" and "76". He looked at the keys, finding that some of the white keys have multiples of 10 written on them.

"What am I supposed to do?" The plane looked, puzzled, at the ice blocks and the keys, turned the propeller, and still didn't understand.

Curious Natalie also went over. She touched a random key with a number other than those five numbers, and was surprised to see a ball shoot from behind the piano. It made a rapid curve in the air like a departing arrow, as if it told them that it was going to hit something.

In a flash of inspiration, Photon realized that the ball was sending them a very important message. He guessed that after each key was pressed a ball would be ejected, and that these balls might break ice blocks. "You press one more key, Natalie! I need to see if my guess is correct."

She hit the highest C, and sure enough, another ball went off, but it just flew by without breaking the ice blocks.

Then Photon patted his chest -- his structure did not allow him to do this, so he had to pretend -- and said firmly, "It seems that my guess is quite correct after all. Well, I think those numbers are the numbers of the keys. Let me try!"

He found the 16th key, which was a C. He pressed down and shot the ball toward the first ice block. "Crack!" The ice block broke.

"Yeah!" Natalie jumped up, "It's like bowling."

"I think so, but not really. You need to see which balls work." Photon laughed and smashed the rest of the ice blocks. The passage was finally broken through. "Wonderful! Yeah!" The cheers of the party pierced the air like sharp swords and penetrated into the concert hall.

The party that had moved on began to search for passage once more. "It's impossible to get through here!" Natalie saw a blind alley, but what was placed there didn't make her back straight away --

A few gilded books were piled up in a corner. After Natalie approached, she found a copy of Music Box Master's Secret, with several pages missing. "Page 300, 301,302... Eek? 306? How come there are three pages missing?"

In addition, the last sentence on Page 302 reminded her of what she had lost,

Below, this book includes a song Music Box. If you like it, please adjust your music box and let it play this song!

"The missing contents appear to be a music score! Maybe we need to find it, or do something about it." She said to herself, and stepped back.

"What's this?" In another blind alley, Ranran saw three sheets of paper stacked together, made of the same material as the Secret, and printed with special notations. The title was "Music Box".

"Wow! Fancy you being here!" Natalie saw the papers in Ranran's hand and cried, "That's it!"