Excerpt from A Spy Among Friends by Ben Macintyre, plus links to reviews, author biography & more

Through Philby, Elliott was introduced to a fraternity of ambitious, clever, hard-drinking intelligence officers, the "Young Turks" of MI5 and MI6. This informal group often gathered, in off-duty hours, at the home of Tomás Harris, a wealthy, half-Spanish art dealer who worked in MI5, where he would play a central role in the great Double Cross deception as the case officer for double agent "Garbo," Juan García Pujol. Harris and his wife, Hilda, were generous hosts, and their Chelsea home, with its large wine cellar, became an open-house salon for spies. "You'd drop in to see who was around," Philby remembered. Here, in an "atmosphere of haute cuisine and grand vin," might be found Philby's friend Guy Burgess, extravagant in his homosexuality, frequently drunk, faintly malodorous, and always supremely entertaining. Here too came their friend Anthony Blunt, a Cambridge art scholar now ensconced at the heart of MI5. Other regulars included Victor, Lord Rothschild, the aristocratic chief of countersabotage at MI5, and Guy Liddell, MI5's head of counterintelligence, whose diaries from the period offer an extraordinary glimpse into this private dining and drinking club within the secret world. From MI6 came Tim Milne, who had been at Westminster with Philby (and was the nephew of Winnie-the- Pooh creator A. A. Milne), Richard Brooman-White, now head of MI6's Iberian operations, and, of course, Nicholas Elliott. Hilda Harris served up sumptuous Spanish meals. Liddell, who had once contemplated a professional career as a musician, would sometimes pick up his cello. Burgess, usually accompanied by his latest rent boy, added scandalous unpredictability. And among them moved Philby, with his aura of smiling charm, holding forth on intelligence matters, provoking arguments ("out of fun rather than malice," Elliott insisted), and dispensing Harris's fine wine in torrential quantities.

Even by the heavy-drinking standards of wartime, the spies were spectacular boozers. Alcohol helped to blunt the stress of clandestine war, serving as both a lubricant and a bond, and the gentlemen's clubs were able to obtain supplies for their members far beyond the reach of ordinary rationed folk. Dennis Wheatley, a novelist who worked in the deception section of British intelligence, described a typical lunch with fellow officers: "To start with we always had two or three Pimm's at a table in the bar, then a so-called 'short-one' well-laced with absinthe. . . . There would be smoked salmon or potted shrimps, then a Dover sole, jugged hare, salmon or game, and a Welsh rarebit to wind up with. Good red or white wine washed this down, and we ended with port or Kümmel." After this blowout, Wheatley tended to sneak off to bed "for an hour to sleep it off" before returning to work.

No one served (or consumed) alcohol with quite the same joie de vivre and determination as Kim Philby. "He was a formidable drinker," Elliott wrote, and held to the arcane theory that "serious drinkers should never take exercise or make sudden or violent movements" since this would provoke a "violent headache." Philby sucked down the drink, and poured it into others, as if on a mission.

Elliott was flattered to find himself in such company and relaxed. Englishmen are naturally reticent. Englishmen of Elliott's class and character even more so, and an upper-class English spy, in wartime, may be the most discreet human being imaginable, his stiff upper lip buttoned down inflexibly. Members of the secret services were forbidden to tell their friends, wives, parents, or children what they did, yet many were drawn to this closed clique, bound by shared secrets others must never know. In the civilian world Elliott never breathed a word about his job. But inside the secular monastery that is MI6, and particularly at Harris's raucous soirees, he was among people he could trust utterly and speak to openly in a way that was impossible outside. "It was an organisation in which a large proportion of one's colleagues, male and female, were personal friends," wrote Elliott. "A sort of convivial camaraderie prevailed, rather like a club, in which we all called each other by our first names, and saw a lot of one another outside the office."

Excerpted from A Spy Among Friends by Ben Macintyre. Copyright © 2014 by Ben Macintyre. Excerpted by permission of Crown. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.