take the lid off

take the lid off  {v. phr.}

1. To let out in the open; divulge.

It's about time to take the lid off the question of how many prisoners of war are still in enemy hands.

2. To start to face an issue.

"The best way to deal with your divorce," the doctor said to Fran, "is to take the lid off of it."

Compare: BLOW THE LID OFF, LET THE CAT OUT OF THE BAG.