Last chapter in Deighton's masterfully entertaining British spy trilogy begun with Berlin Game (1983) and Mexico Set (1984), though--unlike tennis' game/set/match--neither side really wins. Or does some lone player actually make match point? All three books in the group turn on the same plot points: who is the mole, or who is a true defector (rather than KGB plant--or solitary)? In Berlin Game, Bernard Sampson and his independently wealthy wife Fiona (mother of two) both work for MI6 in Operations, with Berlin as their gameboard. The climax reveals Fiona as the treasonous mole. In Mexico Set, Fiona's in East Berlin and rising through the KGB ranks while Bernie sinks ever deeper into muck, under suspicion of disloyalty as ex-husband to an active Russian spy. Fiona has her eye on their two kids, who are still in England and--like a good KGB-nik--is trying to boil Bernie's goose as well. Now, in London Match, Fiona's making a supreme effort to smash Bernie and get her kids. The entire senior staff of London's Foreign Office finds itself on slippery ice against the phantom plays of Moscow Centre. Bernie smells something fishy with their KGB defector Erich Stinnes, who was senior assistant to Fiona in Berlin. Is he a plant? Three of his bits of info have blown the cover on Russian networks and led to low-level captures. But it is a very unexciting spy-song that Mrs. Miller, for example, sings before attempting suicide with aspirin (an attempt remedied by stomach pump) and then being assassinated by the KGB in a car driven into a waterway (when the car's finally hoisted out, it's empty). Who to blame? Well, everything points toward Bret Rensselaer, who's been put in charge of debriefing Stinnes. And slimy Dicky Cruyer, adulterer and German Stations Controller, is all for pushing Bret down the tube. But as the reader will suspect, the hand behind the mole is ferocious Fiona's, and she's just had a secret meet in Holland with her London-based adulterous sister Tessa, with an eye to recapturing her kids. . .There's more here than previously, though Bernie's delicious confrontation with Fiona is reserved for the climax. . .which keeps her offstage until then while the reader longs for some Strindbergian marital storm scenes. The climax is okay but not superterrific--not after a more than 1200-page trilogy. Still, superior fare of its kind.