shyamalan, who credits the development of the movie to a bedtime story he told his children about what happens in their pool at night, wrote the 72-page children's book "lady in the water: a bedtime story" (little, brown, new york, ) to coincide with the movie. the book's illustrations were made by crash mccreery. it was released on the same day as the film, on july 21, 2006.