Billy Harney est né pour être un flic. Le fils du chef des détectives de Chicago, dont la soeur jumelle est également sur la force, Billy suit les règles. Aux côtés de la détective Kate Fenton, la partenaire passionnée de Billy, il n'y a rien qu'il ne sacrifierait pour son travail. Mais Amy Lentini, un avocat trop zélé qui cherche à se faire une réputation, soupçonne Billy de ne pas être le flic qu'il prétend être. Ils sont sur le point d'être liés par plus que leurs carrières.

Being a cop runs in Billy Harney's family. The son of Chicago's Chief of Detectives whose twin sister, Patti, also followed in their father's footsteps, there's nothing Billy won't give up for the job, including his life. Left for dead alongside his tempestuous former partner and a hard-charging assistant district attorney out for blood, Billy miraculously survives. But he remembers nothing about the events leading up to the shootout. Charged with double murder and desperate to clear his name, Billy retraces his steps to get to the bottom of what happened. When he discovers the existence of a little black book that everyone who's anyone in Chicago will stop at nothing to get their hands on, Billy suspects it contains the truth that will either set him free... or confirm his worst fears.