'Don't move!' Shen Yibin was about to shout, but he remembered he was underwater and wearing a diving helmet. So, he followed the diving instructor's directions, paddling his arms and kicking his flippers to swim toward Bald Qiang. When he reached him, Bald Qiang turned his head and gave Shen Yibin a bewildered look before lowering his head again to stare at the round rock. He seemed to have realized something was off, too. 'Why is this rock moving?'
The two of them lay on the lakebed, staring at the rock. Shen Yibin reached out, touched the rock's surface, and gently wiped away the mud, revealing a hard shell with a regular pattern underneath. Bald Qiang seemed to have made a new discovery. He pointed forward, squeaking excitedly and releasing a stream of bubbles.
On the side of the round rock near Bald Qiang, a round hole appeared. A bald head with two beady little eyes popped out of the hole, then quickly retracted.
