Six weeks before she is due to take up her position as the first female head of MI6, Amelia Levene vanishes without a trace.

Her disappearance is the gravest crisis MI6 has faced for more than a decade. There has been no ransom demand, no word from foreign intelligence services, no hint of a defection.

Should news of Levene’s disappearance leak out, the consequences would be catastrophic. But for disgraced MI6 officer Thomas Kell, the crisis offers a chance for redemption. He is approached by his former employers and ordered to find her.

Kell’s search takes him first to France, then North Africa, where he discovers an extraordinary secret hidden deep in Levene's past. It is a secret that could fatally compromise Britain’s national security – and for which Kell himself could pay with his life.