Inception articulate some of the things that have been swirling around his head for the last eight years." DiCaprio and Nolan spent months talking about the screenplay. Nolan took a long time re-writing the script in order "to make sure that the emotional journey of his character was the driving force of the movie." On February 11, 2009, it was announced that Warner Bros. purchased "Inception", a spec script written by Nolan. Principal photography began in Tokyo on June 19, 2009, with the scene where Saito first hires Cobb during a helicopter flight over the city. The production moved to the
Inception rigging the hospital with explosives. Cobb reveals to Ariadne that he and Mal went to Limbo while experimenting with the dream-sharing technology. Sedated for a few hours of real time, they spent fifty years in a dream constructing a world from their shared memories. When Mal refused to return to reality, Cobb used a rudimentary form of inception by reactivating her totem (an object dreamers use to distinguish dreams from reality) and reminding her subconscious that their world was not real. However, when she woke up, Mal still believed that she was dreaming. In an attempt to "wake up" for