It was a lovely sunny afternoon in October. Lying on a park bench was a hardcover book—Plato’s Republic written by Alain Badiou. There were signs of previous ownership, but it was still a very nice copy. Scrawled on a label attached to the cover were the irresistible words: Take me home. I’m a Bookcrossing book.

Bookcrossing is a game of hide-and-seek played with books. The term is originated from its namesake website, which encourages the practice of dropping a book off in an easy-to-find public place (“the wild”) where other people can pick it up, read it and subsequently pass it on. Players of this game, the “bookcrossers”, are known for their creativity when it comes to “themed release”. Fans of Yayoi Kusama might leave copies of their idol’s art books on the bench opposite her works in a museum. Romance novel addicts could let go of their favourite Jane Austen novels at a wedding fair. Avid horror fiction readers would drop a Dan Simmons thriller in a graveyard.

Bookcrossing has been described as a “modern-day message in a bottle”. Like putting messages in bottles and tossing them into the sea, there is a romantic aura to the concept of releasing a book into the wild for a stranger to find. It hints at a sense of mystery and hope, and a serendipitous encounter which may change the finder’s life if it happens to be the right book at just the right time.

While it is difficult to track the movement of a bottle in the ocean, you can track where your book ends up on the BookCrossing website. You can even check who is reading it and what the new reader thinks about it. Each book registered on the website has a unique identification number and a journal entry page. Ideally, whoever finds the book will log on and add a new entry to indicate its whereabouts. As time goes by, a registered book might become a seasoned traveller. It could have been picked up at a café in Brisbane and re-surfaced on an empty seat of a London-bound train, found on a beach in Rio de Janeiro, and then left in a self-service laundry in Cologne. The book currently at the top of the website’s most travelled list, Der seltsame Bücherfreund, has changed hands more than 600 times in ten years, with new readers posting their reviews one after another on its webpage.

In 2005, the BBC took the idea of bookcrossing one step further by releasing 84 copies of Helene Hanff’s 84, Charing Cross Road into the wild, with a note in each copy asking people to call in and share how they came across the book and where it was going. A radio documentary was then made based on the responses. It is fascinating to learn how people from all over the world have been connected by a beautiful book on tour. Helene Hanff, who adored second-hand books and had the habit of giving away books that she was never going to read again, would have hollered “Comrade!” to each one of them.

The bookcrossing movement has slowly taken root in Hong Kong in recent years. The annual Book Crossing Festival organised by Youth Square has become a popular event for book lovers. Over one hundred thousand books have been exchanged since 2011. Last year, a team of HKUST alumni launched OnePile (一沓紙), an award-winning digital platform, to optimise the bookcrossing process. After uploading details of the book they wish to share or reserving a released book on OnePile’s website, users can donate or collect it at OnePile’s book vending machines across the city. Bookcrossing shelves are also available at cafés, shopping malls and some of the GREEN@COMMUNITY Recycling Stores in our neighbourhoods. In addition to these established locations, there are a few niche groups on social networks for the like-minded to exchange or give away books. By sharing books and engaging the community, bookcrossing helps cultivate a love of reading, promote the notion of paying kindness forward, and ultimately enrich the city’s cultural landscape.

The late literary critic George Steiner once said, “A book can wait a thousand years unread until the right reader happens to come along.” Books want to be read. They should neither rot in the landfill nor languish on the shelf gathering dust. Books that have touched your heart can go on to move many more, while those that don’t interest you may just be the gateway to the magical and wonderful world of literature for someone else. So, the next time when you declutter your bookshelves and find books that you are not going to read or re-read, set them free and send them on a journey across time and space.