in the know

[in the know] {adj. phr.}, {informal} Knowing about things thatmost people do not know about; knowing secrets or understanding aspecial subject.

Tina helped Professor Smith make some of the examquestions, and she felt important to be in the know.

In a printshop, Mr. Harvey is in the know, but in a kitchen he can't even cookan egg.

Compare: GET WISE. Contrast: IN THE DARK.