(CNN)Many weekends, high school teacher Emma Smreker can be found searching for treasure. Not at the bottom of the sea -- but at the bottom of bookshelves.
In her search, she hopes to unearth forgotten mementoes left between the pages of used paperbacks at her local book store or thrift shop. She often finds old plane tickets, business cards or receipts hastily used as bookmarks -- small clues that tell a story about the book's previous owner.
But occasionally she strikes gold and finds a poem written between pages, a long-lost photo from a previous reader or a love letter meant for a stranger.
"Through the reselling or donating or borrowing of books, you're connected to another person in another way, especially if we leave notes in margins or a sticky note on a certain page or even a bookmark or a dog-eared page, which, god forbid," said Smreker, who teaches high school French in Oklahoma City.
"It almost takes the solitary out of books because you've connected to this person who had the book before you, as well as their impressions and who they were when they had that book."
Her hobby began with a receipt for a cafe in Montreal that she found tucked between the pages of a French-language book gifted by her husband.
"That receipt kind of immediately transported me there, and I started to think about who this person was who had this book before me, what were they doing, when did they go to this cafe, what their day was like. Then this idea just kind of started to form," Smreker said. "Then before I knew it, I was on the floor in my living room going through on the books in my bookshelf looking to see if there were other little treasures of things that had been left behind."
That initial idea led Smreker to create an Instagram account, @inusedbooks, which features photography of all the mementos she's found since she started flipping through used books two years ago.
But it's not just the treasure hunt and the beautiful back stories of these objects that she loves -- it's also tracking down the previous owners, who have often forgotten the books and the long-lost items.
"I think that's part of the fun of it -- is the surprise of people being like, 'Oh my gosh I had no idea that I had left that in a book,'" she said. "It's just so cool to think of all the things I have in my house all the books and secondhand items that have another story behind them and a history behind them."
From between pages to in print
One of Smreker's best finds yet was an unpublished poem, written out by hand in June of 1893.
Buried in a used book at a flea market, the poem was intended to be published