"Gadget" was a nickname applied to the first atomic device detonated at the Trinity site in 1945, and it's a very appropriate title for Freeling's book. In a book much shorter than many similar techno-thrillers, Freeling presents a credible scenario for assembling a terrorist team, and building and detonating an improvised nuclear device. There's sufficient technical jargon and references to support the human side of the plot, and further enhance the credibility of the scenario. In this book, the bad guys win.