That was the sound made by the Human-faced Strange Fish. Humans could not hear it, but instruments could pick it up.
If Luo Yan had also been a member of that unit, he would have seen rings of ripples continuously spreading across the sonar display.
The Human-faced Strange Fish was issuing a warning.
That was perfectly normal.
However, the commander responsible for leading the main force—a senior colonel of the Yinma Legion—furrowed his brows.
"Something's wrong."
"Why does it look as if 'Wu Zhiqi' doesn't know we're here?"
According to Xia Houwu's calculations, 'Wu Zhiqi' was the master of the Forbidden Land and lived in the waters.
Nothing happening underwater could escape its notice.
That was why, when formulating the operation plan, Xia Houwu had ordered the main force to serve as bait, drawing 'Wu Zhiqi's' attention and luring as many of the Forbidden Land's giant beasts over as possible, creating room for the decapitation team to act.
But now...
It seemed that 'Wu Zhiqi' had not noticed the humans' arrival. It was only after the Human-faced Strange Fish spotted the mechs that it finally issued a warning.
Still, this did not differ too much from the original plan.
After the Human-faced Strange Fish's warning, the Forbidden Land boiled over. The legion's main force had only just stepped into its outskirts, a relatively safe area.
Thus, although giant beasts kept surfacing in the water, the Giant Beast Radar showed that all of them had the blue spectrum of lower-tier beasts.
"Don't let your guard down!"
"Even lower-tier beasts have the home-field advantage in the water. And although we have the Deep Dive System, we're ultimately not as agile as we are on land."
The senior colonel quickly issued orders over the communications channel. "Spread out and advance in with me."