Curiosity
When his brother went missing, he and the guards naturally went to take a look at the CCTV cameras. It was just that he was small and when he encountered a small crowd, he entered a blindspot, disappearing for a bit.
He did, however, surmise that the child was in this building and followed the traces until he ended up seeing that woman.
The way she looked around, how her eyebrows furrowed, how her body moved just attracted his eyes, and made them stick to her.
As someone from an industry where most people he saw were beautiful people, that was saying something.
She was walking around when he saw her, lost, and he couldn't help but follow her. Not just because of his curiosity about the woman, but also because he had a feeling his brother was in the same situation and they could end up in the same place.
She was masked and wearing plain clothing, but he could recognize her. Anyone who had seen her body wouldn't be able to forget it.