Spy?

'...she knew beforehand...' Ozul mused as he returned to their room.

The person in question was right behind him.

When the king mentioned their title of 'Hatchlings', both Kumaou and Rose showed visible confusion. What remained hidden was the fact that only the former showed precisely what he felt, while the latter simply feigned that emotion.

The king might have also noticed if he paid any attention to her, but he was fully focused on him and Kumaou. No one else caught his eyes.

This almost insignificant detail of hers actually revealed a lot about her. 

Except for Ember, the only other party who knew about their origins was now the Steel Mountain kingdom. The Imperial Prince had made sure that the lady knew about them.

'The ones who summoned us also know, but I doubt they would need to send spies to a small kingdom such as this.'