Destination unknown by Agatha Christie

This extensive text from Destination Unknown by Agatha Christie primarily follows the journey of Hilary Craven as she assumes the identity of Olive Betterton at the behest of a mysterious man named Jessop. Hilary, initially planning to end her life, is instead tasked with infiltrating a secret organization to locate Olive's missing scientist husband. This clandestine group, led by the enigmatic Mr. Aristides, is recruiting brilliant scientists under false pretenses, seemingly for financial gain rather than political ideology. Jessop and his French counterpart, Leblanc, are investigating the disappearances of scientists and use Hilary to uncover the location and purpose of Aristides's remote facility. Ultimately, with the help of another undercover operative, Andrew Peters, they expose the organization during an inspection visit, leading to the liberation of the detained scientists and the revelation of the true motives behind Betterton's recruitment and his first wife's death.