Ancient history
Nero carefully observed as each of his members were scanned, even going as far as sensing the aether fluctuations in the area. He was trying to understand what the machine was searching for, and how it worked to begin with, but he couldn't tell much.
The only thing that was obvious was that everyone else took much less time than him to get scanned. Nero came up with multiple theories for why that might be, though none of them made sense. For example, he even thought that maybe having a seventh card on his person, compared to everyone else who only had six, made the machine slow. But that didn't make sense, because everyone was carrying their card cases. They all had many cards with them.