In Sheep's Clothing — Susan May Warren

On the run from the murderer of her best friends, missionary Gracie Benson is all alone in Siberia. What she doesn't know is that she has in her possession a medical secret that will save millions of lives -- or cost hers. Trying to keep her alive is an FSB agent, a man pursued by his own demons, including a killer who destroyed his father's life.

He and Gracie find themselves in a decades-old mystery of betrayal and Cold War secrets. Only with the help of their friends -- a group of Americans and Russians committed to freedom -- can they outwit the old guard...and save Gracie's secret, as well as her life.