It was not currently peak diving season on Yonaguni Island.
This was evident from the dive shop's recent business. Zhang Heng and Han Lu were the second group of tourists to come diving in the past week, and as far as Nelly knew, the first group would be flying home at noon today.
So, barring any surprises, the three of them were the only divers in these waters. That was precisely why Nelly had concluded that the figure she had just seen was Han Lu's—there simply was no fourth person in this stretch of sea.
In other words, Han Lu was likely less than two or three meters away from them. Hope flared up in Nelly again, and she even instinctively ignored the fact that the shadow had moved incredibly fast.
In truth, that was not a speed a human could achieve underwater. But at that moment, Nelly's heart was filled with the joy of finding Han Lu. Even if she had noticed that unreasonable speed, she would probably have explained it away as a current or something similar. And precisely because of that, Han Lu might need their help even more.
Nelly then gestured for Zhang Heng to follow her, but he extended a hand and signaled for her to stay where she was. Then Zhang Heng crossed his clenched fists over his chest before pointing one fist in the direction where the black shadow had vanished.
In diving hand signals, that meant danger.
Since Nelly had seen the black shadow, Zhang Heng certainly had not missed it with his powers of observation. Moreover, unlike Nelly's fleeting glimpse, Zhang Heng's eyes had caught its trajectory. Although it had lasted less than a second, Zhang Heng had already recognized what it was.
Yes, that black shadow was one of those