Her book, The Eleventh Day: The Full Story of 9/11 and Osama Bin Laden, co-authored by her husband Anthony Summers, was a finalist for the Pulitzer Prize in History.

[3][4] During her time at George Washington University, Swan interned with the non-profit military policy think tank, The Center for Defense Information[5] and with political magazine, The National Journal.

In 1989, she was hired by Anthony Summers to conduct research for his book Official and Confidential: The Secret Life of J Edgar Hoover, a biography of the powerful long-time Director of the Federal Bureau of Investigation.

Among the book's most sensational revelations was comedian and fellow Rat Pack member, Jerry Lewis’ recollection that Sinatra had regularly carried money for the mob.

[17] According to a review in The Telegraph [UK], the authors’ "principal criticisms are that the Bush administration was asleep at the switch on 9/11; that vital intelligence was ignored; that the FBI and CIA did not share information; and that Saudi Arabia was intimately connected to al-Qaeda and is sometimes overindulged by the US."

The reviewer argued, however, that there was "no real evidence" for the claims of Summers' and Swan's sources that the CIA negotiated with Osama bin Laden prior to those attacks, or that the Agency attempted to recruit two of the hijackers as agents.

[27] The book was written with the cooperation of the family of Admiral Husband E. Kimmel, who was Commander-in-Chief of the Pacific Fleet at the time of the attack, and included never-before-published documents from U.S., British, and Dutch archives.

[32] Summers’ and Swan's 2005 biography of Frank Sinatra contained an allegation that, in 1969, the then 53-year-old singer had sexually assaulted a young woman in one of the guest bungalows on his Palm Beach estate.