Who/What is outside in this sentence?
-What? Then what’s in that?
-The greatest enemy of empress is outside.
Empress is outside now or it (is inside now) will be the greatest enemy when it will be outside?Speakers are in the basement. Empress is outside. Speakers found a cocoon in the basement and speak about what is inside it. But I don't understand, the author focused attention on the fact that the Empress outside, or it will be an enemy to the Empress?

Question

Who/What is outside in this sentence?
-What? Then what’s in that?
-The greatest enemy of empress is outside.
Empress is outside now or it (is inside now) will be the greatest enemy when it will be outside?Speakers are in the basement. Empress is outside. Speakers found a cocoon in the basement and speak about what is inside it. But I don't understand, the author focused attention on the fact that the Empress outside, or it will be an enemy to the Empress?

Answer

With the new information, it sounds like the speakers are saying the cacoon is not a danger to the empress. The people speaking or someone else, but not in the cacoon, are the greatest enemy. The author might be infering that the speakers are the greatest enemy to the empress.

Answer

"When there is no enemy within, the enemies outside cannot hurt you"

I need more context and a clearer question to better understand you. But, I'll try to answer you.

The Empress is inside a castle. Her greatest enemy is outside the castle. She doesn't have any major enemies inside of the castle.