Following the events of A Trace of Smoke, journalist Hannah Vogel has been in hiding in Bolivia with her young ward, Anton, for the past three years. She believes she has outwitted Ernst Röhm, the head of the Nazi Party’s Storm Troopers who believes himself to be the boy’s father, so she seizes the offer from a newspaper to cover the journey of a zeppelin from South America to Switzerland, particularly as it will allow her a rare opportunity to meet with her lover, Boris Krause. When the zeppelin is diverted to Germany, she knows she’s walked straight into a trap.

Röhm, facing expulsion from the party as a result of rumors of his homosexuality, has decided to claim his alleged son, and marry Hannah as a beard. Unfortunately for him, his solution has come too late. Hitler has supplanted the Storm Troopers with the SS, headed by Himmler, and the resulting purge, forever known as The Night of the Long Knives, has begun. Hannah manages to escape in the melee, while Röhm faces a firing squad. She and Anton were separated, and Hannah must enlist all her allies - and a few of her enemies - to track him down before the Gestapo can.

With nowhere else to turn, Hannah finds herself at Boris’ door in a wedding dress. She expects a safe haven, but she learns that her presence and search for Anton are putting Boris at risk. During her absence he has been helping Jews escape and he is already under suspicion. Finally she traces Anton to the home of Röhm’s mother, who offers a deal - her son's body in exchange for Anton. Traveling to Berlin, Hannah is caught up in the Nazi’s continuing purge and must learn to trust - and protect - those she has loved, and hated, in order to survive.