A Russian defector is found brutally murdered in a London hotel. Only four people knew he had turned - the four most important and powerful figures in Whitehall. There's only one conclusion - a mole has infiltrated the highest levels of the nation's security. Operating in secret from within Westminster's darkest corners, former spy Solomon Vine must uncover the traitor. Because Britain's future hangs in the balance. And with it the fate of the whole world.

Only she knows the truth. Only he can tell the world. Vienna, 1946. A brilliant German scientist spirited out of the ruins Nazi Europe in search of a new life. Moscow, 1964. A rising star of the British diplomatic service whose job is not what it seems. London, the present day. A once promising academic offered an opportunity to seal his place in history. Their stories, their lives, and the fate of the world, are bound by a single document: The Scarlet Papers. The devastating secrets contained within teased by a brief invitation: Tomorrow 11AM. Take a cab and pay in cash. Tell no one.

Red Square, 1985. The naked body of a young man is left outside the walls of the Kremlin: frozen solid - like marble to the touch - and missing the little finger from his right hand. A week later Alex Marston, the headstrong 15-year-old daughter of the British ambassador, disappears. Army intelligence officer Tom Fox, posted to Moscow to keep him from telling the truth to a government committee, is asked to help find her. It's a shot at redemption. But Russia is reluctant to give up the worst of her secrets.

When disgraced spy Solomon Vine's friend and rival Gabriel Wilde vanishes without trace, it's only Vine who might be able to discover what has happened to him. A single missing file holds the key. That, too, is gone. But its contents, Vine is told, are incendiary. There were few Wilde could trust. And being one of them appears to have fatal consequences. But as Vine's off-the-books investigation begins to reveal the shocking truth, he realizes there's much more at stake than one man's life.

In the aftermath of a global pandemic, a beautiful and charismatic human rights activist is murdered live on the internet at the British Embassy in Paris. It is a mystery that no one wants solved.