THE MASTER SPY
by Phillip Knightley
Knopf; 292 pages; $19.95
In the extensive postwar literature of espionage and double agentry, fact and fiction tend to blur. Was Magnus Pym the name of John le Carre's perfect spy? Or was it Guy Burgess? Pym and Burgess, Donald Maclean and Toby Esterhase -- characters from the shadow world of MI6 and the KGB -- seem equally real, equally fanciful.
And so it was with Harold Adrian Russell ("Kim") Philby, whose exploits as a Soviet mole inside Britain's Secret Intelligence Service seem breathtaking enough to have been crafted by a master of the thriller...