Sam McCready has served with distinction for seven years as chief of the cover operations desk of Britain's Secret Intelligence Service, a post that is the culmination of a brilliant career as an inventive and intrepid field agent. But times have changed. A high-level policy decision demands that the SIS strip away its old-style operatives, and the first to be targeted for retirement is the freewheeling McCready.

When a body is hauled from the River Tyne, Sarah Tucker heads to Newcastle for a closer look. She identifies the dead woman as Private Detective Zoë Boehm, but putting a name to the corpse only raises further questions. Did Zoë kill herself, or did one of her old cases come back to haunt her? Coincidence is an excuse that soon appears pretty unconvincing. Sarah can’t leave until she’s found the answers to her questions, however dangerous they might turn out to be.

Plan Aurora, hatched in a remote dacha in the forest outside Moscow and initiated with relentless brilliance and skill, is a plan within a plan that, in its spine-chilling ingenuity, breaches the ultra-secret Fourth Protocol and turns the fears that shaped it into a living nightmare. A crack Soviet agent, placed under cover in a quiet English country town, begins to assemble a jigsaw of devastation.

CIA Case Officer Sam Joseph is dispatched to Paris to recruit Syrian Palace official Mariam Haddad. The two fall into a forbidden relationship, which supercharges Haddad's recruitment and creates unspeakable danger when they enter Damascus to find the man responsible for the disappearance of an American spy. But the cat-and-mouse chase for the killer soon leads to a trail of high-profile assassinations and the discovery of a dark secret at the heart of the Syrian regime.

After an unremarkable interview, Circus agent George Smiley determines the subject of a standard security check—a civil servant in the Foreign Office named Samuel Fennan—poses no threat, nor presents any reason for suspicion of espionage. Hours later, Samuel Fennan is found dead by suicide. Suddenly finding himself under intense scrutiny, Smiley realizes the Circus intends to blame him for Fennan's death. Rather than remain idle, Smiley begins his own investigation into the nature of the man's demise.