Marven continued to walk forward with an uneasy feeling. Finally, we finally reached the end of the secret passage. But when he saw the end of the secret passage, his heart sank.

At the end of the passage there is a wall that blocks the passage. The wall was not made of brick, but a whole large stone. Not even a crevice.

Marven studied for a long time, but he couldn't find any mechanism to open the door.

At this time, he suddenly heard the sound of "boom", which was very similar to the sound of ten thousand horses galloping under the effect of the echo of the passage. The sound stopped after only a few seconds, and silence followed.

Marven had no choice but to go back. It was until I was exhausted and hit another wall.

Marven froze. There is a wall to go forward, and a wall to go back. Where was the entrance to the secret passage just now?

When entering this secret passage, Marven didn't even think about making a mark. This secret passage is so long, where can I go to find the entrance?

At this time, Marven finally understood what the sound of ten thousand horses galloping. It was the sound of the entrance to the secret passage being closed.

"Cane Grandpa, wake up. I'm lost. Marven shook his cane.

Under the guidance of Grandpa Cane, Marven finally returned to the entrance of the secret passage.

Fortunately, I brought a cane to navigate, otherwise I would have been trapped in this secret passage. Marven couldn't help but be a little afraid.

This entrance doesn't look any different from the rest of the passage. Marven searched for a long time before he found a mechanism on the top of his head.

It took him seven or eight jumps to stab the trap with his cane. With a slight touch, a brick bounced out of the wall. Marven picked up the brick and looked at it, and there was a map carved on it. Marven didn't have time to look at the map, so he first looked at the hole where the brick fell out. Inside the cave is another mechanism. Marven pulled the mechanism, and a stone door crept open, revealing the entrance. Marven hurriedly jumped out of the entrance.

Mia and Biting were terrified when they saw the entrance to the secret passage closed. It wasn't until the entrance to the secret passage reopened and Marven came out of the secret passage that he settled down.

"There's a map here, there must be a way to get out" Marven put the bricks on the ground and studied them attentively.

Marven tilted his head to look at the map while eating what Mia had given him. But after watching it for a long time, I still can't understand it.

Marven reluctantly said to Mia, "This map is more complicated than the treasure map we used to play. Do you understand? ”

Mia shook her head.

Biting stood up with his two hind legs, crossed his two front legs, and said to Marven proudly: "I can understand this map." ”

"What?" Marven remembered the experience with the fireflies. At that time, I also got a road map that I couldn't understand, and in the end, I bit it and understood it.

Biting took Marven back to the secret passage, walked a few hundred meters to the right, and found another mechanism. After pressing the mechanism down, I heard a roar coming from the direction of the hall.

When they returned to the hall, an entrance appeared on the wall, and inside was an upward staircase.

Marven, Mia, and Biting went up the steps together, and after turning a few corners, they finally saw the light on the steps. It's not the lights, it's the sun.

Finally from the bottom back to the surface.

Marven happily ran up the steps. However, he didn't find out until he got up the steps. Instead of returning to the surface, they came to an aquarium-like glass enclosure.