Ответ в теме: English idioms

Main Aditor

to keep (a person) in the dark — to hide things from a person; to keep things secret
to be in the dark about — not to know about or not to understand fully, not to be in the know
to keep (a thing) dark — to keep it a secret

1. He must keep Bunder absolutely and permanently in the dark about Dogson and his mission to reveal the secrets of the drug traffic. (J. Wain)
2. Besides, she was in the dark about his feeling now. (J. Gals¬ worthy)
3. I don’t see how anyone else but Parker could have sent it. Depend upon it, his own man. But keep it dark — we don’t want to alarm him just yet. (A. Christie)