Karla's Choice: A John le Carré Novel, Nick Harkaway
Harkaway, a pseudonym for Nicholas Cornwwell, son of David Cornwell, real name of John le Carré, offers this novel as a bridge between The Spy Who Came in from the Cold and Tinker, Tailor, Soldier, Spy. It is a George Smiley book and is pretty satisfying.
When the story begins, Smiley has left the Circus following the debacle of the operation in Spy and has reconciled with his wife Lady Ann. The two have even gone on a European holiday to patch up their fractured marriage, broken by Ann's repeated infidelities. And then Control has one last mission for Smiley. . . .
The plot involves a man who might be a sleeper agent for the USSR, his (probable) college-age son, who has been arrested behind the Iron Curtain. The man, a respectable literary agent, vanishes in quest of the young man, leaving his pretty young assistant, a thoroughly Anglicized Hungarian, in the lurch. Control interests himself in the situation and gradually the Circus begins to suspect that the elusive Soviet spymaster Karla is involved. Though Smiley agrees to come into the case only as an advisor and strategist, before he knows it, he has to step in as a field agent, hoping to protect the young woman and to extract the boy, his father, and perhaps his mother from Hungary.
The tone echoes the books we know, and we revisit many characters: Smiley and Ann, Peter Guillam, Bill Haydon, Toby Esterhase, Connie Sachs, and even Hans-Dieter Mundt, the untrustworthy double agent who first appeared in Call for the Dead. Karla himself does a few walk-ons, and we get a chunk of his backstory. It isn't quite le Carré (at times the central figures seem somewhat out of character), but it's a satisfying, complexly plotted read.