The appearance of monster inside the ruins

(From MC's perspective)

Ruins section area -2,

Night,

After exploration, everyone used this wide spacious hall to set up a tent. Seven different tents were arranged circularly.

Inside one of the tents,

Garrett Marsh pondered deeply. 

"This building used to be a storage house. But it's a pity, I came across nothing except the gold sacks," he grumbled.

Should I give him or not? He became hesitant. Earlier he thought no one would find anything about this building. But as usual, the leader came up with a result.

Then he thought about observing the gold stone. In curiosity, he takes out a few gold stones from the gold sacks and places them on the ground. 

The stone is not completely bright. The gold stone faded over time and now it looked like some kind of rock. But he believes that it is similar to modern-day gems.

While he was observing something sinister taking place outside. 

Outside of the building,