```html
As the two Imperial Guards and Zhou Ling departed, everyone breathed a sigh of relief.
"Alas..." Prince Song shook his head.
No matter what, Da Meng has lost face this time.
The Imperial Guard actually allowed two Evil Sect monsters to slip in.
Chu Zhiyuan said, "Your Highness, there's no need to blame yourself. These Evil Sect monsters are becoming more formidable. New secret techniques emerge one after another, making them impossible to guard against."
"Is this a new secret technique?"
"It should be a new secret technique. If such techniques existed earlier, the Court might have been infiltrated long ago. But since it's just now showing up, there's still time to curb it."
"A truly terrifying secret technique," Prince Song said gravely.
This is a technique that can deceive a Grandmaster.
The Imperial Guard is responsible for protecting the Imperial Palace, though only its outer perimeter.