Specimen Days is a novel by American author Michael Cunninghan published in 2005. It is primarily based on the poems of Walt Whitman, and the title is based off one of Whitman's works. The story is divided into three separate sections: one taking place in future, one in the present, and one in the past. The film rights to the book are owned by Scott Rudin, who also made another one of Cunningham's works, The Hours, into an Academy Award winning movie.
The plot is comprised of three distinct short stories: In the Machine, The Children's Crusade, and Like Beauty. In the Machine takes place in Industrial Revolution era New York, and is a supernatural, spiritual story. The Children's Crusade is a noir thriller, also set in New York, but this time in the 21st century, centering around a travelling terrorist band that is detonating bombs arbitrarily around the city. Like Beauty, the final story, is set in futuristic New York, and involves refugees from another planet flooding into the city.
Walt Whitman is a constant presence throughout the novel, whether as a spiritual apparition, quoted through poems, or as a motif.