"Ouch... It hurts..."

"Where is this?"

"It looks so strange, and there is a special smell..."

"We've never been anywhere like this before."

"But I think it is so familiar here?"

Hearing the robots talking, William could not help wanting to know immediately where they were. He stood up and was surprised to find that his head was touching the ceiling.

"Where on earth is this?" He asked.

Suddenly something flew over and fell to the ground. He picked it up. It was a small fluorescent whiteboard that glowed a pale milky light like moonlight.

"And what is this for?" Ranran was also very puzzled.

"Wait." Cried William, "There's writing on it."

"Oh, let me see!" Ranran leaned her head gently on his shoulder, looking at the fading-in handwriting together with him. It was so neat, very much like his own, that he was puzzled.

Dear William,

I'm glad to see you awake again safe and sound. I've watched you sleep for hours. You're not cold, are you?

"What am I cold for? I'm still sweating, huh." His lips curled in disdain.

The writing continued to emerge:

That's good. You must be wondering what just happened. Now let me tell you.

You're right. The balls that you just encountered in a black hole are made of positive matter. So the energy core released a lot of energy to keep you from being torn apart, but in the end you are defeated by strong gravity, aren't you? And because the black hole is so massive, its gravity actually folded space-time into five dimensions! That is to say, that void is actually five-dimensional space, and through this five-dimensional space you have come to another universe!

"What! Another universe!" He was surprised and pleased, and there was a faint expression of worry on his face.

"Another universe? ! Oh my god! What a feat we have accomplished!" Cried all the others.

William still couldn't believe the words on the whiteboard. "Why is this like in another universe?" He looked around him, and it was like a basement! Look, the ceiling was not very high and his head could just touch it. The light was so poor that some of the objects in the corners could hardly be seen. Sofas were arranged along the wall, intermingled with worn cardboard boxes. A huge locker stood behind them. Several ragged overcoats and a large packet of papers were jumbled in it.

It was all so strange, and yet so familiar. William still couldn't believe it was another universe!

"We could have basements like this in our own universe!" He said, puzzled.

The handwriting then read,

If you see this, you will believe it.

Then, their computer automatically turned on and ran Map. A few seconds later, something desperate happened -- words like this appeared on the screen:

Failed to get location information, because the current map data does not exist. Please check the connection and try again.

"This is the end! This must be an area unfamiliar to the map!" Natalie, the racing car, cried desperately.

"I'll see what he is going to write." Said William calmly.

Don't worry, baby. You will find a way back, just by using your energy core again. But it's not on this planet right now, and you can't get it right now. It has run out of energy. Only by charging it can you return to the universe where you belong. And the places that you're going to pass through --- "checkpoints" for short --- are going to have a small amount of energy recorded. That is to say, as soon as you go through there, you will get the corresponding energy. You'll have to go to three planets, including this one, and finally you will be able to get the energy core full of energy.

I know you're very adventurous, baby. So I won't let you down. Have fun!

The whiteboard disappeared and William was left standing there, frozen.

"How can this be...? Am I dreaming?" He reached for the wall and found that it was indeed a solid wall. He then looked at the sofas and realized that they, too, were sleeping quietly against the wall. The dilapidated storage locker was really a storage of a few clothes and a large package of paper. The cold, damp, dark and disappointing basement yanked him out of his fanciful, beautiful dream and abandoned him mercilessly.

Suddenly the atmosphere became eerie again, and the air around became a lot heavier at once. Fear, out of nowhere, rose and roared against him like an angry sea. Instinctively, he raised his laser gun and was ready to shoot.

But he was puzzled then, for the fear that had been so clear had gone away, and had come again from another direction. This time it was mixed with a low whisper. It drew nearer and nearer to him, but it teased him, for it withdrew completely just as William felt that he was about to be completely surrounded by it.

"You're not dreaming, William. It's true." Ranran said desperately.

"I know, dear Ranran." William turned to her, smiled faintly, and said, "I know that no matter how much I wish this were a dream, we have come to a whole new universe; I know that no matter how much we try to escape, or hold back, we have to adventure to go back. I know that no matter what darkness and confusion we may experience, as long as we keep moving forward, victory is in front of us. So let's go, to the first checkpoint."

The map on the computer now had new data. "Look! The checkpoint information is loaded!" Said Photon excitedly.

They all crowded round to see what was going on. Map showed that they were currently on a planet orbiting a blue giant.

Then the following dialog popped up:

Gentlemen, you're in the basement. And now all you have to do is to get out of this basement. Unfortunately, the key is hidden in a dark box on the wall. Only if you find a way to open the dark box will you get out. Don't worry. I'm sure you'll succeed. Two hints: 1. There's a switch in the locker. 2. Don't let go of all the places that are painted green.

"There's a switch in the locker! Find it!" Said William, running there. He opened the doors and found a device with a black base and a metal knob in a drawer. There were three symbols, "I", "1" and "2". "I" was marked at the bottom of the knob, and where "1" and "2" were marked there was a distinct feeling of frustration.

"That means those two are the outputs." He muttered to himself, telling the others, "It's a single-pole double-throw switch! That's what we're looking for!"

"Good!" Ranran cheered.

"Shouldn't we also look at the green marks?" Photon prompted William. "Oh yes! There's a green mark near there." Then he ran back to look, and sure enough, he found another clue,

There are some objects in the carton. You need it to open the dark box.

Natalie found batteries, some wires, two coils with vastly different turns, an iron core and a spark plug.

"What on earth is all this for?" She asked, puzzled.

"Don't worry, I need to see other green marks. The other hints must be there."

At the next green mark William saw these words.

The batteries only provide 12 volts. It takes at least 10,000 volts to spark a spark plug.

"It is obvious that the coil and core are used to assemble a simple transformer." He thought. He seemed to have an idea in his mind now, but he needed more hints.

The third mark successfully gave the hint,

This is a neon tube, and when it breaks down, it emits light. The surface of the dark box is coated with cadmium sulfide, a photosensitive material whose resistance decreases when exposed to stronger light. The opening and closing of the dark box is controlled by a motor.

"Neon... Cadmium sulfide... Motor... Oh, I see! Natalie, give me all that! I know how to open it!"

He found all the components and succeeded in connecting them together into a complete circuit. He inserted the spark plug in the neon tube. Aimed at the obvious layer of cadmium sulfide coating, he flipped the switch without hesitation. The spark plug rattled a loud electric noise, while the spark licked the neon with its bright white fangs. With this unique lick, it glows red. A moment later, there was a gap on the coating.

It looked like they were almost there, for all that was left was the words:

1 + 1.1 + 10 + 1.2+ 100 + 1.3 + 1,000 + 1.4 + 10,000 + 1.5 = ?

"11,117.5!" William blurted out without thinking.

The gap opened wide and a small white key met their eyes. It also glowed white, as if it had just been dyed by moonlight.

"Let's go!" Ranran said. Photon put the key into the lock, twisted it gently, and unlocked the door.

In front of them was a tunnel, and the handwriting next to it was the last hint they saw in the basement,

Go up the tunnel. When you see the blue arrow, turn left and enter the forest. You will see a wide road covered with maple leaves. Keep walking along it. After about two or three kilometers, you'll see a wooden gate. Go in. Your first checkpoint is over there. You will also meet a cat named Thomson, who will tell you some other information. Besides, the ship is about a kilometer away from Thomson's house. Finally, good luck.

"Bye, basement." William looked reluctantly at the door, then turned his head and led the others gradually to the ground.