Yixiong looked at the pictures. It was true what Jingkang said. The uppermost picture, the two pentagons, might be an indication of the context of the five pictures below.

"The crowbar definitely symbolizes metal. Then the drink bottle symbolizes water," said Yiren.

"The stove symbolizes fire, while the table symbolizes wood," said Jingkang.

"How can a house symbolize earth?" Yixiong asked himself.

"Maybe because the house is built using bricks. Bricks are made of soil. Soil is earth," said Jingkang.

"We managed to solve this riddle," Yiren cheered.

"Don't get excited just yet. We haven't succeeded yet," Yixiong said. "We still don't know what that has to do with this message from the kidnappers."

"Maybe the kidnappers sent us here to get the real message. They realized the police had been watching closely, so they used a secret way to get the message out to us," Jingkang said.

Yixiong nodded. He looked at the pool that lay in front of him. Each edge of this pool must represent one of the five elements.

"Let's just ask the people who work in this park. Is it true that the shape of this pool is related to the five elements?" said Yiren.

"Who should we ask? Hardly anyone here. The janitors in this park might as well have all gone home." Jingkang said.

"There's one," Jingkang pointed to someone who seemed to have just appeared out of nowhere.

"Eh, isn't that the janitor we asked about earlier?" Yixiong said.

"That's right, Sir! That's him," said Jingkang.

Jingkang got up from the bench and walked over to the person. He then engages in a conversation with that person. The person pointed this way and that. It was obvious that he was explaining something to Jingkang.

Jingkang returned to where they were sitting while jogging. His face was so bright.

"It turns out that our guess is not wrong! Each side of this pool indeed symbolizes the five elements. In the past, on each side, there was a small statue symbolizing the five elements. The statues were located on each outer side of this pool. Exactly behind the bench in the middle. This side where we are sitting is the side that represents earth!"

Yiren smiled widely. He seemed thrilled.

"Let me see the paper again, Sir!" Jingkang said.

Yixiong handed the paper to the young man.

"Didn't you change the size ratio of each object in these pictures?" Jingkang asked.

"No," said Yixiong. "I copied on a size scale that I tried to be as close as possible to the original image."

"So this picture of the house is indeed much bigger than the other four pictures?"

"Yes. I was also a bit surprised. But I just copy it as is. Indeed, the picture of the house is much bigger. But at first I thought it was because the size of the house was indeed much bigger than the size of other objects," said Yixiong.

"In this case, maybe size symbolizes priority," said Yiren.

"You mean, the original message from the kidnappers, if it really exists, lies on the side that represents earth?" Yixiong asked.

"There's no harm in trying to find it, right?" Yiren said.

The three of them looked at each other. Yixiong nodded. He agreed with Yiren.

They rose from the bench they were sitting on. After inching a few meters, they looked at the outside of the pentagon.

"Where do you think the crooks hid their messages?" Yixiong muttered.

"The objects on each side of this pentagon are these stone benches. So it's very likely that the messages have a lot to do with these benches.

Yixiong remembered the basement under their backyard. The place where they got the keys was under a stone bench in the basement. The stone benches in this park were much bigger than the stone benches in their basement. Even if they only focused on one side of the pentagon, there wasn't much they could do. It's still impossible to lift the stone benches on the side of the earth element.

"Let's check the bench in the middle," said Jingkang.

The three of them then moved to the bench in the middle. The bench they were sitting on was the one on the far left on the earth element side.

"You know this bench is very heavy," Yixiong said to Jingkang.

"I know, Sir, but I don't think the criminals left any clues under this stone bench," said Jingkang. "This is a public park. There's no way they'd come here and then dare to lift this stone bench to put something under it. Their actions would surely attract the attention of many people."

"Look at this!" Yiren pointed at the side of the stone bench.

There was a hole in one side of the stone bench. The stone bench turned out to be different from the other stone benches.

"Could it be that the criminals put something in this hole?" Jingkang asked.

Yixiong was reminded of the underground passage that led to the basement under their backyard. The hole in the stone bench was about the same size as the dog hole in the secret passage.

"Let me try to enter," said Yiren.

"Don't, Sir! Let me do it," said Jingkang.

Yixiong grabbed Yiren's arm. "I know you're younger than me, so you're most likely still more flexible and fitter. But we have to be realistic. Among the three of us, Jingkang is the youngest. So, this time, we'd better let him try this."

Yiren nodded.

"Thank you, Sir for the opportunity you gave me." Jingkang looked so excited. He immediately crouched down. The young man then lay down in front of the hole in the stone bench. Slowly, he crept into the hole. After he entered to the limit of his waist, he stopped.

After a minute Jingkang was in that position, Yixiong started to worry. But his anxiety vanished as Jingkang inched backwards. Slowly, he came out of the hole.

After Jingkang's whole body came out of the hole, he immediately got up and sat on the stone bench. He took a deep breath. His face looked thrilled. There was a plastic package in his hand.

"I think we should go back now. Soon this park will close. All visitors must leave!" Those were the first words Jingkang said after he came out of the hole.

Yixiong and Yiren nodded. Jingkang got up from the stone bench. The three of them then walked out of the garden.