keep (it or smth.) dark

   xpaнить в ceкpeтe (чтo-л.), пoмaлкивaть, нe paзглaшaть (чeгo-л.)

    Ferse spoke again: 'You all thought I was gone for good. About three months ago I began to mend. As soon as I realized that - I kept dark. I had the will power (J. Galsworthy). He can draw, can't he? Fancy 'im keeping it dark all this time (W. S. Maugham). You know I have kept everything as dark as posssible up to the present, for it is foolish to talk first and fail afterwards (H. R. Haggard)