Despite Yuri's sudden arrival, Andrew did not panic, because he could see and control everything that was happening inside Dunnas Palace, so he limited himself to telling Oliver, Castor, and Vala to be attentive and concentrate on observing her.
With Marie and Aki's pregnancies, Vala had become the commander of Shadow's agents and although they had only recently met her, these young agents had no problem following her.
Although Vala knew that Andrew had complete control over Dunnas Palace, the moment she was informed of Yuri's arrival, she assigned an agent to watch her from the shadows.
Yuri is a woman with surprising intuition, which even allows her to identify a person's strength and intentions to a certain level, but she is not an expert, so she would never be able to identify that someone was watching her.
