How to say "本应秘而不宣" (běn yīng mì ér bù xuān) in Chinese dialogue

běnyīngérxuān

it should've been kept secret.

Idioms & Colloquial Expressions
Grammar Patterns
INTERACTIVE SCRIPT TIMELINE
LINE 0116:29
shòu
diǎn
shēng
biàn

Once something happened at the ceremony,

LINE 0216:31
PLAYING SCENE
běn
yīng
ér
xuān

it should've been kept secret.

LINE 0316:32
jìng
xìn
chuán
xùn

Instead, the signal drums were sounded. - The entire city heard about it. -Something happened at the Directorate of Astronomy!

Show Information
Source MediaTV Series
Season & EpisodeS1 E1
Timestamp16:31
TMDB ID289209