"Choose a corner first."

Klein followed the instructions and found a random corner.

Before he brandished the shovel, a line of golden words appeared once again.

[This corner is dangerous.]

Klein went to the other side.

[This corner is dangerous.]

The same hint!

With no other choice, Klein could only shift another location.

[This corner is fine.]

[Choose a location.]

Dig!

Klein brandished his shovel.

[System notification: Sand+1]

[Sand+1]

[Sand+1]

...

Klein didn't really need sand.

The main reason was that it took up too much space.

However, there was no need to pay attention to this at the moment.

He directly dug down into the catacombs.

Klein wanted to use the sand to create a cushion.

He dug hard.

Soon, the 20-meter-deep underground cave was dug.

Another shovel.

It was empty!

Klein looked down.

A black hole appeared.

'What could be inside?' Klein thought to himself, unsure.

However, Klein decided to try the situation first.

Klein thought.

There seemed to be the sound of a unit of sand falling.

He pricked up his ears to listen.

He couldn't hear the sound of sand falling to the ground at all.

"Is the sound blocked?" Klein muttered.

Whatever. He continued to discharge sand.

After throwing a few units of sand, Klein loosened his grip and descended freely.

His gaze was constantly focused on the ground below.

It didn't take long before he reached the bottom.

The entire height of the fall was about two meters.

As he had been prepared, he didn't get hurt.

However, he didn't see the sand that had been laid down earlier. Anything that was thrown past the black hole would disappear!

The spot where Klein stood belonged to the high platform in the third catacombs.

It was next to a corner of the catacombs.

It formed a slope.

The first thing Klein noticed was the treasure chest leaning against the wall.

It quickly slid down the slope.

In front of him was a bronze treasure chest.

[Bronze Treasure Chest: One level higher than a wooden treasure chest. There's a high probability of a small surprise, but there might also be a hidden danger.]

[There's a unique blueprint inside this bronze treasure chest. There's no danger.]

There were two different notes.

Klein opened the bronze treasure chest with ease after reading them.

There was a blueprint inside.

[System notification: Bronze Treasure Chest+1]

[System notification: Bronze treasure chest can be split into 4 copper pieces. Do you wish to split it?]

[System notification: Excellent Condenser Bluepring+1]

[System notification: Do you wish to learn an Excellent Condenser Blueprint?]

Klein didn't bother with the bronze treasure chest for the time being.

The blueprint was clearly more attractive to him.

He flipped through it carefully.

There were dense lines and patterns on the blueprint.

In addition, there were many unknown words.

[Excellent Water Condenser Blueprint: It belongs to daily use runic devices. Together, it can condense water vapor in the air. The efficiency isn't bad. Every adventurer will fall in love with it.]

In the subterranean world, the quality of tools and equipment varied. They could be classified as: ordinary, excellent, perfect, rare, epic, legendary, or divine.

If an item was damaged, its grade wouldn't be displayed.

For example, the runic base was currently damaged, so the grade couldn't be seen.

Only after it was repaired would the grade be displayed.

"This... is a runic device?"

Klein checked it a few times.

There was no such thing on the manufacturing list.

Klein was certain that it was a good item.

It was just like a runic base. Just by having the word 'runic', it possessed a mystical ability.

"Learn!"

The blueprint in Klein's hand turned into a purple light and instantly entered his body.

[Learning successful!]

Following the system's prompt, Klein silently chanted in his heart, 'Open the manufacturing page.'

Instantly, a row of synthesis lists appeared in front of Klein.

He searched for the water condenser and then automatically slid the interface to the end.

[Excellent Water Condenser: Copper 0/4, Iron 0/2, Wood 2/2, Water Rune 0/1, Fire Rune 0/1]

Of the five synthetic materials, only wood was sufficient.

If the copper treasure chest was decomposed, Klein would probably be able to gather the copper.

The names of these two runes sound very impressive.

Klein thought to himself.

On the other hand, in order to save water, he hadn't been willing to take a sip even though his mouth was already parched.

However, Klein had more important things to do, so he didn't have the time to care about anything else.

Copper treasure chest decomposition.

[System notification: Copper Block+4]

With that, he needed to gather the other three materials for the Excellent Water Condenser.

The remaining two runes were definitely not easy to obtain.

However, it was also possible that Klein was overthinking things.

Perhaps the runes weren't anything valuable.

Klein continued digging.

The next two times, he chose to go forward and dig to the right.

In total, he obtained "4 iron blocks, 4 wood, 2 wheat bread, and 1 mineral water."

The length of the tunnel was different every time he dug.

It varied from a few meters to dozens of meters.

Furthermore, some of the catacombs didn't look as simple as he had imagined.

They were even very troublesome.

From the looks of it, Klein had to be careful in his next step.