the darkest hour is just before the dawn

(proverb)when things seem to be at their worst they are about to start improving

(谚)黎明前最黑暗

keep something dark

keep something secret from other people

保密

a shot (或 stab) in the dark

an act whose outcome cannot be foreseen; a mere guess

瞎碰；臆测

in the dark

In secret

秘密地

high-level decisions made in the dark.

高层决定是秘密地制定的

In a state of ignorance; uninformed

一无所知地；未通知地

kept me in the dark about their plans.

我对他们的计划一无所知