Amazon.com description: Product Description: Blatty se baso, para crear a su protagonista, en un hecho real ocurrido en la decada de los cuarenta. Una nina de apenas once anos sufre terribles transformaciones, sobre todo en su comportamiento. Ni medicos, ni cientificos, ni psicologos seran capaces de hallar la causa de tal estado y paulatinamente todo ira apuntando hacia la hipotesis de que la nina esta poseida por el demonio. / Blatty was inspired by a true event during the 1940s to create his protagonist. A girl of just eleven years old undergoes terrible changes. Doctors, scientists, and psychologists are all unable to find the cause of her condition. They begin to suggest that she may be possessed by the devil.