At 7:30 a.m. the cabs pull up to a modern office building in northern Virginia. About 30 young men and women shuffle into what looks like a doctor’s office on the first floor. The CIA doesn’t encourage fraternization at the nearby hotel where they’ve been put up, but the candidates still managed to find one another and stayed up late talking. They all want to join an elite fraternity of spies. But first they must make it through what CIA psychologists fondly call “Hell Week.”

More than 100,000 inquire about agency jobs every year. For those who want to be part of the Directorate of Operations, the CIA’s clandestine arm, the psychological and security screening is one of the most complex and time-consuming in the U.S. government. Few CIA officers ever betray their country, but those who do-like Edward Lee Howard, who defected to the Soviet Union in 1985 and is accused of unmasking the Moscow station-create havoc for the agency. CIA spies are now being sent to more dangerous places to collect more complicated secrets. Hell Week examines how they’ll hold up under the strain.

The screening actually begins months earlier. CIA recruiters cultivate “spotters” in universities and businesses-ex-spooks or professors who pass along an agency phone number to good prospects. A prospect who strikes the recruiter as someone worth pursuing is handed a 16-page application. Agency screeners then spend months evaluating qualifications and looking for red flags: financial problems, scrapes with the law, signs that the applicant might be a potential mole.

If there are no hang-ups, the applicant undergoes “assessment and evaluation”: three hours of intelligence and personality tests, then an hour with a CIA psychologist. In a “Reasoning Ability” test, a candidate is presented with a family tree, then asked if deductive statements about genetic disorders in the tree are true or false. Much of spying is making sense out of byzantine secrets. One personality test has 480 true-false questions: “I like ‘Alice in Wonderland’ by Lewis Carroll”; “I gossip a little at times.” Another measures whether the candidate can adapt to the rigors of spying: would he mind living in a country “with a prolonged rainy season” or working in a job where “you do not receive recognition”?

The loner in a John le Carre novel is not the spy the CIA wants. A case officer has to recruit foreign assets and therefore must be good at socializing. Does the applicant mind striking up conversations with strangers, the psychologist asks. Does he enjoy parties? If the testers like what they see so far, the applicant begins the next phase: “suitability screening,” which asks if candidates “have something in their background or character that would rule them out,” a CIA psychologist explains.

A nurse leads the men and women through blue doors to rooms for a three-hour medical exam. After the physical, a bus takes them to another building in northern Virginia (applicants never set foot inside Langley) for a polygraph exam. Everyone’s still in a cheery mood. But after three hours with the polygraphist and a psychologist, candidates are somber as they return to the first building. “Confessionals with no absolution at the end are not pleasant,” says the psychologist.

Applicants are run through more tests. Do you have trouble sleeping at night? Those who do may find high-pressure clandestine work difficult. Do you form lasting relationships with people? The best case officers befriend their foreign agents but can’t be blind to the possibility that some may be doubles. Describe your father. Upbringing is important. Spoiled children often argue with their bosses as adults or move from job to job. The Directorate of Operations hates turnover: disgruntled exspies may blab about secrets they knew.

By now wrung out and paranoid, each candidate is marched upstairs into a bare office for a final session with a psychiatrist. No one is secretly videotaped or recorded. But some suspect they are and ask if a camera is behind a framed picture hanging on the wall or if a strange-looking box on the ceiling is a bug. The picture is for decoration and the box is a smoke detector, the psychiatrist says pleasantly-then notes the question on the applicant’s file.

The psychiatrist continues to probe. How careful is this person? How quickly does he think? Espionage is like combat-long periods of boredom punctuated by brief moments of terror. Moral dilemmas are thrown out to test conceptions of right and wrong. “Your wife is dying of cancer. You don’t have enough money for her treatment. A nearby lab has the drug that can save her life and you know someone who can steal it. But that would compromise the lab’s research. What would you do?”

After Hell Week, psychiatrists deliberate about each applicant. Those who pass move to the final phase: security screening. A team interviews friends and former employers, running credit and police checks. CIA stations in the countries the applicant has visited hunt for signals of security threats. All told, it takes as long as nine months to be hired as a spy. Says a CIA official: “We tell our candidates, ‘Don’t quit your day job until you finally hear from us’.