Vatican City, 29 September 1978: the world wakes to the shocking news that Pope John Paul I is dead, just a month after his accession.

Thirty years later, in London, young journalist Sarah Monteiro receives a mysterious package. Enclosed is a list of names and a coded message.

Moments later a masked assassin attempts to silence her for ever. It seems Sarah holds the key to unveiling a deadly secret – a plot that implicates unscrupulous mercenaries and crooked politicians, and which goes to the very heart of the Vatican. Sarah has no choice but to run, forced into a ruthless game of cat-and-mouse. She can trust no one, especially when her father's name appears on the incriminating list.

Sarah finds herself at the centre of a world-wide conspiracy its keepers will stop at nothing to protect.