Andrew Niccol, the screenwriter behind 'The Truman Show' and director of 1997's futuristic 'Gattaca,' wrote the script and will likely direct the feature, which will be sold at the 2011 Cannes Film Festival later this month.
In 'The Host,' alien parasites called "Souls" invade human bodies and take over a person's consciousness. Ronan will play Melanie, who is captured by the aliens and implanted by a Soul called Wanderer. Wanderer attempts to get Melanie to give up the last remaining humans on Earth, but finds she is different from any other host in her unwillingness to give up her consciousness. He ends up attempting to connect with Melanie's old life.
Meyer was initially reluctant to turn the book into a film, but her fears were set aside when Niccol agreed to pen the script. Meyer is reportedly a fan of 'Gattaca' and his script for 'The Truman Show'; she hand-picked him to take on the project.
Niccol had intended to direct the film but left the project earlier this year to direct 'Now' with Justin Timberlake, Amanda Seyfried and Cillian Murphy. However, that movie has already finished production, and with filming on 'The Host' not expected to begin until later this year, it is likely he will return to the project.