Han Xiao frowned. "No! I have to go in and take a look! Things in there might not be what we think!"
Song Ning stopped him. "Blow the whistle first! Get Chen Liang and the others over here!"
Han Xiao nodded, immediately took the whistle from his left pocket, and blew their agreed signal.
Soon, a few faint answering whistles sounded in the distance.
Han Xiao bent down and tightened his shoelaces. "It'll take them a while to get here! We don't know what's happened to Xiong Gang. I'll go in and check first!"
Song Ning said, "Whatever's going on inside, come back and let me know!"
"All right!"
Han Xiao stepped onto the plank and crossed it in a few strides. Just as Xiong Gang had done, he pushed the iron cover inward and went headfirst into the opening.
Song Ning remembered to remind him, "Be careful!"
"Okay! There really is a passage in here, but it's very dark..."
Han Xiao crawled all the way inside, and the iron cover dropped back into place on its own, blocking the opening.
It was exactly what had happened when Xiong Gang went in.
But just as the iron cover shut...
Song Ning heard Han Xiao give a short, urgent cry from inside. "Song Ning-"
His voice cut off abruptly.
Then there was silence.
Song Ning's heart lurched, and a fine layer of cold sweat instantly broke out over her body.
She hurriedly shouted, "Han Xiao! Han Xiao! What happened in there? Answer me!"
There was still nothing but silence.
She looked toward the gap they had entered through. It was still pitch-black over there.
Chen Liang's group had been searching in the opposite direction. They must have gone quite a distance by now, and it would take them time to get