An alleged serial killer cooling his heels in a maximum-security prison, two improbably dogged private investigators determined to prove his innocence, a criminal Secretary of Homeland Security, and corruption and brutality in the highest echelons of the American intelligence community make up David Baldacci\'s mildly entertaining spy thriller The Sixth Man. This is the fifth book in the Sean King and Michelle Maxwell series. King and Maxwell, both formerly with the Secret Service, are on their way to meet King\'s friend and mentor Ted Bergin, a lawyer who wants to hire them as investigators to help him fight the case of Edgar Roy, who has an eidetic memory and is America\'s foremost intelligence analyst. He can run his eyes over gigabytes of intelligence information appearing on The Wall — a 2x2.5-metre screen on which information flows — and come up with patterns, predicting when and where the next terrorist attack is likely to take place. Roy is the kind of man who casually mentally records the 168 vehicles passing by in a 332-kilometre journey and also memorises their number plates for good measure. But six bodies have been dug out from his farm. The ball is set rolling when, on their way to meet Bergin, King and Maxwell find the lawyer seated in a car by the side of the road — with a bullet in the head. Why was he killed? Who killed him? These are the questions the duo has to find the answers to. They start off by bringing Bergin\'s assistant on their side. But is she what she appears to be? Powerful forces want to nail Roy and will stop at nothing to ensure that happens. The Wall is the brainchild of billionaire private defence contractor Peter Bunting. While it has helped streamline America\'s colossal intelligence-gathering operation like never before, it has also taken away federal funding from the multiple intelligence agencies in Washington. This has particularly affected the Department of Homeland Security. And secretary Ellen Foster isn\'t amused. In cahoots with his rival Mason Quantrell — who has made a fortune overbilling the United States government — she wants to destroy Bunting and his E-Program. Quantrell once employed Bunting but watched in horror as his protégé raced ahead of him. Plainly put, Roy is Bunting\'s ace — and Bunting believes the man is innocent and wants him out of prison. As the two investigators dig deeper, people start dying. In one rented car after another, King and Maxwell find themselves driving up and down America\'s east coast in their attempt to link the dots. A lot of jaws and knees are broken along the way, especially by Maxwell. Enter Kelly Paul, Roy\'s half sister who has an intelligence background herself. She is, of course, determined to prove her brother\'s innocence and joins hands with the investigators. The cat-and-mouse game is now in full swing, culminating in an unconvincing \"hostage exchange\" scene in Washington DC. Unfortunately, Baldacci\'s novel is replete with appalling dialogue, especially between the two protagonists. The clichéd wisecracks, more appropriate for a bad Hollywood spy flick, make you wince. The book seems to lack substance; there is too much running around and not enough plot — you can more or less see where it is all headed. Besides, a strong grounding in international affairs is a prerequisite for anyone attempting to write spy thrillers. But Baldacci\'s research leaves much to be desired (we are informed, for instance, that Anbar is a province in Afghanistan). Buy this book only if it is the only thriller you can get your hands on at an airport bookshop, with time to kill.