After a visit to her family in Louisville, young Mercy Randolph returns to her new home in Sweetriver, Kansas, and suddenly finds herself in the midst of dangers moving as fast as a tornado.

Meanwhile, Jeremiah must learn to deal with his new faith and his new love—while risking everything he has to save his reckless nephew from the evil plans of the Medicine Bow Gang. Mercy is tested in ways she could never have imagined and must decide if she has the boldness and wisdom to thwart the gang’s schemes. Will her bravery be enough to guarantee her a future with Jeremiah?

With their beloved plantation, Greenwood, now a vital link in the Underground Railroad, Richmond and Carolyn Davidson must balance the need for safety with their commitment to helping the many runaways who appear at their door. Compounding their danger, the Davidson’s neighbors, the Beaumonts, do not approve of their decision—and view them with suspicion.

The danger intensifies when the Davidsons’ older son, Seth, becomes engaged to Veronica, the Beaumonts’ beautiful, scheming daughter—against her parents’ wishes. As the two families are swept up in events leading up to the Civil War, they must choose sides—in a conflict that will change their lives forever.