FROM JANUARY 2003 to May 2004, Walsh and Ballester tracked down nearly every piece of information that could possibly yield a connection between Armstrong and the topic of doping. They spoke with former teammates, team directors, and team doctors. They also interviewed sports physiologists to learn about how performance-enhancing drugs work and spoke with confessed dopers, like France's Jerome Chiotti, to find out how drugs are used by cyclists.

Walsh says that he and Ballester interviewed more than 55 people in the course of researching the book. "It should have been 255," admits Walsh, "but we didn't have time. We both still had full-time jobs."

The end result is a sprawling collection of interviews, statistics, timelines, and newspaper accounts, but no proof against Armstrong. Yet Walsh and Ballester say that any definitive standard of proof was impossible to meet. Sources, they claim, refused to come forward, often citing their fear that Armstrong would retaliate and damage their careers and reputations. "People refused out of what could happen to them," claims Ballester.

Still, setting aside those allegations in the book that can be dismissed as purely speculative—such as Walsh and Ballester's tenuous attempt to raise the possibility that Armstrong developed cancer because of his alleged doping program—the authors offer several charges that stand out. One is an anecdote recounted by New Zealander Stephen Swart, in which he, Armstrong, Frankie Andreu, and others allegedly discussed, in the spring of 1995, starting a doping program for the Motorola team that would include the use of EPO. According to the book, Swart said, "Lance fully participated in the discussion and his opinion was to go with it."

In another significant allegation, Walsh and Ballester describe a scene that allegedly took place in an Indianapolis hospital room in October 1996. They write that a number of Armstrong's friends and acquaintances were visiting him after the surgery to remove his cancer: Frankie Andreu and his future wife, Betsy; Chris Carmichael and his wife, Paige; Armstrong's girlfriend Lisa Shiels; and Stéphanie McIlvain, a representative from Armstrong's sunglasses sponsor, Oakley. The authors allege that Armstrong, in a conversation with his doctors that took place in the room, admitted that he had used EPO and human growth hormone—a natural hormone that, when taken in sufficient doses, can stimulate lean muscle growth and aid in recovery.

Other serious allegations come from O'Reilly, the Postal team's head soigneur in 1999 and 2000, who had kept a diary of her time with the team. When Outside reached her by phone, O'Reilly declined to comment on this story, but in L.A. Confidentiel she is quoted as saying that in May 1999 she was given a box of unlabeled pills by Johan Bruyneel, Postal's team director, and asked to drive across the border of Spain and France and deliver them to Armstrong in a McDonald's parking lot. She also claimed in the book that she helped Armstrong apply makeup to conceal arm bruises caused by syringes, and she talks in the book of discarding syringes and other medical waste on the team's behalf. O'Reilly alleges she was party to the forging of a backdated medical certificate that explained Armstrong's positive urine test for steroids, and she also alleges that, after that incident, Armstrong told her, "Emma, now you know enough to bring me down."

L.A. Confidentiel also provides an account of an August 2001 telephone conversation between Armstrong and three-time Tour winner Greg LeMond, who had been publicly critical of Armstrong's ties to Ferrari. The alleged conversation was recounted by LeMond's wife, Kathy, who, according to Walsh, wrote down her memory of the exchange immediately after the call.

The book describes how the LeMonds were getting into their car when an agitated Armstrong called Greg to complain about his comments. Kathy says she overheard Armstrong challenge her husband to say that he had never taken EPO during his professional career.

"What makes you say I've taken EPO?" Greg replied.

According to the book, Kathy's memory of Armstrong's response was "Go on, everyone takes EPO."

Then the book details the background of Michele Ferrari to make the case that Armstrong's relationship with him should invite people to entertain suspicions about Armstrong. Walsh quotes the February 2002 testimony of Italian pro cyclist Filippo Simeoni, a client of Ferrari's, during the criminal court proceedings that led to Ferrari's conviction in 2004. The book describes Simeoni, an admitted doper, explaining how, in 1996 and 1997, he had taken EPO based on Ferrari's instructions, and how they later discussed adding testosterone to his program.

On the whole, because Walsh and Ballester's evidence in the book is circumstantial, no single piece of it has the power of truth. But Walsh believes the sheer volume of suggestive evidence makes it convincing.

"I find it hard to believe a person could go to our book with an open mind about Lance Armstrong," he says, "and come away still believing in him."