Gu Shengyin reached out and gently pressed a spot on the soft couch.
A secret compartment under the pillow appeared; she glanced at it and saw various scattered small items inside.
She reached out and took a small white porcelain bottle, opened it, and poured out the bright red pill inside.
Gu Shengyin brought it to her nose and gave it a light sniff, releasing a rich, sweet aroma.
This was how the Seo Imperial Family controlled these Hidden Guards.
Every three months, the Hidden Guards must go to their master to collect an antidote.
Moreover, the antidote for each member of the imperial family was different, meaning it was impossible to betray their master and serve another.
Gu Shengyin put the bottle back, restored the pillow to its original state, and slowly lay down.
The reason Ying Qi was hesitant to act was not only because many people in the capital were familiar with Eldest Princess Yong Le, which made her cautious, but probably also because of this reason.
