Arlington librarians are hoping to solve a mystery, and it’s not one they've read in a Nancy Drew novel.

Last week, someone dropped off material for the Friends of the Library book sale and tucked inside was “something of value,” said Peter Golkin, Arlington Public Library spokesman. Volunteers sorting the items found the material.

“This was kind of hidden, so this person who donated didn’t even realize what was in there, and we would like to give it back to them,” Golkin said.

Golkin wouldn’t give away any more clues about the item so that librarians can verify the true owner.

“But you can say the valuable material is tucked away in a safe, so we aren’t taking any chances there,” Golkin said.

Did you donate something to the Friends of the Library book sale last week? Contact Arlington Central Library Manager Margaret Brown at 703-228-5952 to discuss what was lost.