It's not every woman who runs a background check on a guy who's asking her out on a date. But if you were a secret agent working undercover, you would be extra careful too. In 1997 Valerie Plame was being courted by a man who had served as a U.S. diplomat in nine countries, many in Africa, and possessed about as high a security clearance as any spy could hope for, but Plame was taking no chances. It was only after several months of dating Ambassador Joseph Wilson that Plame, supposedly a private energy analyst, revealed the name of her true employer: the CIA. Hearing this, Wilson had a question for his future wife: "Is Valerie your real name?"

   Security agencies all over the world are now quietly running Plame's name through their data banks, immigration records and computer hard drives as the White House leak scandal continues to percolate. Officials with two foreign governments told TIME that their spy catchers are quietly checking on whether Plame had worked on their soil and, if so, what she had done there. Which means if one theme of the Administration leak scandal concerns political vengeance — did the White House reveal Plame's identity in order to punish Wilson for his public criticism of the case for war with Iraq? — another theme is about damage. What has been lost, and who has been compromised because of the leak of one spy's name? And who, if anyone, will pay for that disclosure?

   Officials in George W. Bush's Administration were able to show progress by the Justice Department into who might have leaked Plame's name to syndicated columnist Robert Novak back in July — whether they really wanted to get to the bottom of the matter or not. Government sources tell TIME that the FBI has interviewed more than two dozen officials in several Washington offices, including White House press secretary Scott McClellan and Bush political adviser Karl Rove as well as other West Wing aides. The FBI has obtained desk diaries and phone records and is examining the network server that handles White House e-mail. So far, the initial face-to-face interviews, which are typically not done under oath, have been somewhat informal. In a sign of high-level interest in the leak case, several of the interviews were conducted by veteran G-man John Eckenrode, the lead FBI official on the investigation. Agents asked interviewees to keep mum about their chats so as not to disclose the government's strategy. Both McClellan and Rove declined to comment on the probe.

   Plame was outed as part of a longtime dispute between Bush moderates and hard-liners over the strengths and shortcomings of the agency's prewar intelligence on Saddam Hussein. Wilson, who had been sent by the CIA to Niger in 2002 to check out rumors that Saddam was seeking nuclear fuel there, went public with his skepticism about that charge in a New York Times op-ed piece in July. Because Wilson's article was the first deep dent in the Bush team's claims about the justification for war, Administration officials were soon working quietly behind the scenes, steering reporters away from his conclusions, dismissing his work as shoddy and charging that he got the Niger mission only because his wife worked on proliferation issues at the CIA. It was that last detail — and the added fact that his wife worked undercover — that sparked a federal criminal probe into disclosing a covert officer's name.

   Some Bush partisans have suggested that the outing of Plame is no big deal, that she was "just an analyst" or maybe, as a G.O.P. Congressman told CNN, "a glorified secretary." But the facts tell otherwise. Plame was, for starters, a former NOC — that is, a spy with nonofficial cover who worked overseas as a private individual with no apparent connection to the U.S. government. NOCs are among the government's most closely guarded secrets, because they often work for real or fictive private companies overseas and are set loose to spy solo. NOCs are harder to train, more expensive to place and can remain undercover longer than conventional spooks. They can also go places and see people whom those under official cover cannot. They are in some ways the most vulnerable of all clandestine officers, since they have no claim to diplomatic immunity if they get caught.

   Plame worked as a spy internationally in more than one role. Fred Rustmann, a former CIA official who put in 24 years as a spymaster and was Plame's boss for a few years, says Plame worked under official cover in Europe in the early 1990s — say, as a U.S. embassy attache — before switching to nonofficial cover a few years later. Mostly Plame posed as a business analyst or a student in what Rustmann describes as a "nice European city." Plame was never a so-called deep-cover NOC, he said, meaning the agency did not create a complex cover story about her education, background, job, personal life and even hobbies and habits that would stand up to intense scrutiny by foreign governments. "[NOCs] are on corporate rolls, and if anybody calls the corporation, the secretary says, 'Yeah, he works for us,'" says Rustmann. "The degree of backstopping to a NOC's cover is a very good indication of how deep that cover really is."

   For decades, a varying number of NOCs (the exact figure is classified) have been installed abroad in big multinational corporations, small companies or bogus academic posts. The more genteel rules of traditional espionage do not apply to NOCs. When the Soviets caught a diplomat doing spy work during the cold war, they roughed him up a little and sent him home. Unmasked NOCs, on the other hand, have met with much harsher fates: CIA officer Hugh Redmond was caught in Shanghai in 1951 posing as an employee of a British import-export company and spent 19 years in a Chinese prison before dying there. In early 1995 the French rolled up five CIA officers, including a woman who had been working as a NOC under business cover for about five years. Although the NOC caught in Paris in 1995 was simply sent home, "it might not have been so easy in an Arab country," says a former CIA official familiar with the matter. "[NOCs] have no diplomatic status, so they can end up in slammers."

   A NOC's ability to run silent and deep has led Ohio Republican Mike DeWine, a member of the Senate Intelligence Committee, to press the CIA to invest more heavily in NOC officers, adding that the CIA's traditional spies, posing as diplomats and trained to infiltrate governments, are not well positioned to penetrate stateless gangs of terrorists who don't go to embassy parties. DeWine called for a larger NOC program in a report issued by Congress in July — and many ex-spooks were surprised when the CIA cleared the document for public consumption. But the agency has resisted such efforts before, arguing that NOCs are too expensive and too dangerous to expand the program by much.

   Though Plame's cover is now blown, it probably began to unravel years ago when Wilson first asked her out. Rustmann describes Plame as an "exceptional officer" but says her ability to remain under cover was jeopardized by her marriage in 1998 to the higher-profile American diplomat. Plame all but came in from the cold last week, making her first public appearance, at a Washington lunch in honor of her husband, who was receiving an award for whistle blowing. The blown spy's one not-so-secret request? No photographs, please.