Wanting in a way, yet strangely engrossing

READERS of a certain vintage would know Deep Throat. No, not the 1972 Linda Lovelace pornographic hit Deep Throat (shame on you!) but the informant behind the Watergate scandal, one of the most notorious in American history, that brought down the presidency of Richard M Nixon.

The identity of this government whistleblower nicknamed Deep Throat was an intensely speculated mystery for three decades until Mark Felt, former associate director of the FBI, dramatically outed himself in 2005, three years before dying at the age of 95.

Mark Felt: The Man Who Brought Down the White House, based on Felt's 2006 memoir co-authored by John O Connor, is his insider account of how FBI's No 2 became, to some, a patriot, and, to others, a rat.