According to Koontz in the afterword of a 2004 paperback reissue, he and an unnamed director developed the book into a screenplay independently. They then took it to various studios to pitch the project.
According to Koontz in the afterword of a 2004 paperback reissue, he and an unknown director created the book as a screenplay on their own initiative. They then presented it to several movie production companies for possible development.