Chapter 1031: My Perfect Maid is on Fire.
Despite having told Rena that she wouldn't tell Victor about her 'mistake,' those words were only said to calm Rena down about the repercussions of her actions... A strategy that backfired when Rena herself became suspicious of Kaguya because she wasn't reporting the truth to the Emperor.
The Dragoness internally huffed when she remembered Rena's attitude, despite it being an attitude she quite approved of, speaking volumes about Rena's loyalty to the Emperor. Kaguya wondered if Rena was underestimating the Emperor too much.
Victor had eyes and ears EVERYWHERE. This expression wasn't just figurative, as not only did he have his subordinates to act as his eyes and ears, but he could also observe the entire planet if he so desired.