"Secret," Kieran replied to Perry Kaner ambiguously.
He wouldn't tell her that it was all Frost Wolf and Fire Raven's efforts in digging those enemies out.
In fact, using Frost Wolf's sense of smell and Fire Raven's sight, Kieran already got a hold of the whereabouts of the other Viper Sect branch and he'd even understood a few of their operational points.
In simpler words, if these enemies hadn't cared about the captives he took earlier, Kieran was ready to take the fight to them himself.
However, from the looks of it now, that was completely unnecessary.
Other than that, it allowed Kieran to understand that there might be one or more valuable captives among the six that he captured earlier.
After getting Kieran's answer, Perry Kaner was stunned, and before she could ask again, Kieran went straight towards Mary with a smile.