The rays were emitted by five inconspicuous instruments embedded in the cave wall.

The holes were arranged evenly from top to bottom, sealing the entrance completely.

Of course, infrared radiation is not lethal.

Its real function is to provide intrusion warnings.

Seeing this, Liu Kai was even more pleasantly surprised.

With such careful and cautious defenses, the probability of it being their hideout is very high!

For ordinary people.

It is virtually impossible to pass through infrared rays without damaging the detector.

But for Liu Kai, it was just a matter of teleporting half a meter.

Easily evaded the first layer of detection.

But Liu Kai really didn't expect that there would be three more layers in the tunnel that was more than 180 meters long!

As he stealthily infiltrated deeper and deeper, he took in more and more of the interior.

Liu Kai felt increasingly alarmed as he looked at it.

The number of people and equipment inside exceeded his expectations.

It has a silent generator for power supply, lighting, heating, and exhaust fans.

There were also pots and pans, sleeping bags and tents, guns and ammunition, food and water.

The staff there had a clear division of labor.

Besides the armed guards, there were also some people digging holes with shovels.

It seems they wanted to widen the tunnel to accommodate more equipment.

In a location resembling a command post, a huge map was hanging.

The temperature there must be quite high, so a muscular man of average height was shirtless.

He also had a white cloth towel tied around his head, with a red circular pattern in the center.

The burly man was sitting in front of a huge radio-shaped communication device, his mouth moving incessantly.

I don't know what they're talking about.

If nothing unexpected happens, this person should be the direct commander here.

From guards to engineers.

There were about 50 people in total inside the spacious tunnel!