Dorothy McKibbin decides to take a job as a secretary, knowing it's mysterious in nature because it has something to do with the war effort. Then she meets her new boss—Oppenheimer—and is instantly struck by his magnetism and just knows she has to be involved in whatever he's doing.
Meanwhile, scientists have been hired for the project and are simply given letters telling them to report to an address in Santa Fe, and that they'll find out how to complete their trip upon arrival there. When they arrive, they met with Dorothy McKibbin, who becomes commonly known as the "Gatekeeper".
Her job is to write out security passes for the newcomers, tell them to never refer to each other as "doctor" or "professor" while in town to prevent drawing attention to their presence, and then give them directions to Los Alamos.
Despite all of the scientists' precautions, the people of Santa Fe know something is up: Suddenly there are a bunch of people with European accents everywhere and long lines of army trucks heading to the hills.
Pretty amazing rumors start spreading about what's going on at Los Alamos.
To defray the growing interest in what's happening up on "The Hill," Oppenheimer asks Robert and Charlotte Serber (his right-hand man and his right-hand man's wife) to go into town and spread the "rumor" that they're building an electric rocket.
Despite their best efforts, no one seems to take their bait.