He quickly ran back a short distance and then made a call using his old cell phone.

Fortunately, Captain Liu's phone, though old, was still quite responsive.

Even in this desolate wilderness, the signal was not lost.

Lin Xue then activated her radar system again, and a new route map appeared before her eyes.

Sure enough, there was a secret passage under the small wooden house leading to other places.

"I didn't expect this radar system to be so useful; it can even see the underground tunnels from the surface!"

Lin Xue breathed a deep sigh of relief. It seemed that even without taking the secret passage, she had a way to keep up with the group ahead.

"Have Comrade Lin and the others gone in?"

Soon, Captain Liu finished his call and returned.

"Those people have already gone inside, but the door to the cabin isn't closed, and it seems there are still people inside!"

Lin Xue could see faint voices coming from inside the house.

"What are we going to do? We can't get around those people into the secret passage. What if they have cell phones to communicate? If we capture these two or three people, the people in the tunnel might know that we've been exposed!"

Captain Liu was getting anxious, especially since his phone battery was running low, and he was worried he might lose contact with his brothers.

“Let’s go straight up there. There’s a difference between hollow and solid ground. I can tell the difference to some extent, but we still have to wait for Xiao Zheng to come!”

Lin Xue also noticed that Captain Liu's phone screen showed low battery. Under the cover of her backpack, she took out a power bank from her storage space and handed it to him.