Nest of the monarch / Kay Kenyon.

Enhanced descriptions from Syndetics:

Kim Tavistock, undercover in Berlin as the wife of a British diplomat, uncovers a massive conspiracy that could change the course of the war--and she's the only one in position to stop it in the electrifying conclusion to the Dark Talents series.

November, 1936. Kim Tavistock is in Berlin on her first Continental mission for SIS, the British intelligence service. Her cover: a sham marriage to a handsome, ambitious British consul. Kim makes the diplomatic party circuit with him, hobnobbing with Nazi officials, hoping for a spill that will unlock a secret operation called Monarch . Berlin is a glittering city celebrating Germany's resurgence, but Nazi brutality darkens the lives of many. When Kim befriends Hannah Linz, a member of the Jewish resistance, she sets in motion events that will bring her into the center of a vast conspiracy.

Forging an alliance with Hannah and her partisans, Kim discovers the alarming purpose of Monarch : the creation of a company of enforcers with augmented Talents and strange appetites. Called the Progeny, they have begun to compel citizen obedience with physical and spiritual terror. Soon Kim is swept up in a race to stop the coming deployment of the Progeny into Europe. Aligned against her are forces she could never have foreseen, including the very intelligence service she loves; a Russian woman, the queen of all Talents, who fled the Bolsheviks in 1917; and the ruthless SS officer whose dominance and rare charisma may lead to Kim's downfall. To stop Monarch and the subversion of Europe, she must do more than use her Talent, wits, and courage. She must step into the abyss of unbounded power, even to the point of annihilation. Does the human race have limits? Kim does not want to know the answer. But it is coming.