CHICAGO (CBS) — A real life mystery at a North Shore public library has people scratching their heads.

Volunteers with the Wilmette Public Library’s “Books Down Under” store got a surprise last week when they opened, what they thought was a book donated to the shop. Instead, it was a fake book with a hollowed out interior meant to hide things. WBBM’s Bernie Tafoya reports.

READ MORE: Chicago Weather: Winter Weather Advisory Remains In Parts Of Illinois And Indiana; Lake Effect Snow Lingers

Stashed inside it were various items of jewelry, coins, and keepsakes.

Now, Friends of the Wilmette Public Library wants to find who the memorabilia belongs to.

READ MORE: Snow, Black Ice Cause Multi-Vehicle Pile Up On Interstate 90

Friends of the Wilmette Public Library, which runs the store, has found other items, such as, greeting cards, airline tickets, and the occasional dollar bill stuck inside the pages of real donated books.

But Friday’s discovery of a cache of jewelry is a first, said Susan Morrison, volunteer manager of the shop in the library’s lower level where books are sold to benefit library programs such as its Summer Reading Club.

Morrison was unsure how much value the rings, bracelets, necklace and other pieces might have beyond the sentimental. Other items found in the gutted copy of “Wait Till Next Year” by William Goldman and Mike Lupica include, a D.A.R (Daughters of the American Revolution) medal and a pocket watch with an inscription that reads “Presented to C.F. Buck by employees, Department of Agriculture, 1930.” Also inside was a card on which is written “Mare dear, for something ‘old’ thought that you would enjoy these precious bits of (illegible), she gave them to me.”

Morrison hopes the owner of the belongings steps forward to claim them.

MORE NEWS: Upcoming Report From Northwestern Medicine Gives Clues About How Long COVID-19 Symptoms Can Linger

WBBM Producer Helen Marshall contributed to this story