Emma Watson Hides Books in London Subway

She played book fairy for a day.

"I've been hiding copies of Mom & Me & Mom for Books on the Underground on the tube today! See if you can find one tomorrow!" she wrote in a Facebook photo.

The star also posted a video of herself leaving books along an escalator handrail.

Watson hid a total of 100 copies of the book as part of Books on the Underground's campaign to encourage commuters to read more on the subway -- and share books they enjoy by leaving one behind.

Earlier this year, Watson started an online feminist book club called Our Shared Shelf. "Mom & Me & Mom" is her book club's November/December selection.

Riders lucky enough to find one of the copies also got a special note from Watson that she inscribed inside each of the books.