A Russian arrives in Singapore with a secret to sell. When the Russian is killed and Sam Joseph, the CIA officer dispatched for the meet, goes missing, Artemis Procter is made a scapegoat and run out of the service. Traded back in a spy swap, Sam appears at Procter’s central Florida doorstep months later with an explosive secret: there is a Russian mole hidden deep within the upper reaches of CIA. As Procter and Sam investigate, they arrive at a shortlist of suspects made up of both Procter’s closest friends and fiercest enemies. The hunt soon requires Procter to dredge up her own checkered past in service of CIA, placing her and Sam into the sights of a savvy Russian spymaster who will protect Moscow’s mole in Langley at all costs, even if it means wreaking bloody havoc across the United States.