A scribe known only as the Ghost (EWAN McGREGOR) has just taken a replacement assignment to complete the ghost writing of former British Prime Minister Adam Lang's (PIERCE BROSNAN) autobiography. Approved by the politico's lawyer, Sidney Kroll (TIMOTHY HUTTON), and given just one month to complete the work by publishing head John Maddox (JAMES BELUSHI), the Ghost travels from Britain to Lang's American compound on Martha's Vineyard.
There, he meets Lang's staff, including his personal assistant, Amelia Bly (KIM CATTRALL), who's overly protective of the manuscript, and bodyguard Barry (TIM FARADAY) who's assigned to protect Lang's wife, Ruth (OLIVIA WILLIAMS). She isn't particularly happy with his behavior of recent, and that's exacerbated when he returns to the compound only to hear that Robert Rycart (ROBERT PUGH), one of his former cabinet members that he fired, is now alleging he broke international law by ordering the illegal transfer of suspected terrorists to American officials.
That only makes the pending autobiography even more anticipated, and the Ghost's deadline is moved up two weeks to get it to market faster. Yet, as he works on that, he also starts to investigate the recent death of his immediate predecessor. Ruled as a drunken accident off a ferry, the incident raises the Ghost's suspicions as clues and other info -- such as the previous ghost writer's contact not only with Rycart but also Professor Paul Emmett (TOM WILKINSON) who knew the Langs back in their school days -- come to light.
As the Ghost continues to dig deeper, he soon realizes that isn't making certain parties happy and thus he begins to worry about his safety, all as the heat continues to be turned up on Lang.