Seven years ago, orphaned and alone, Em finally arrived at a new home in Iowa after riding the orphan train. But secrets from her past haunt her, and her new life in the Western wilderness is a rough one. When her guardian is shot and killed, Em, now 19, finally has the chance to search for her long-lost sister, but she won't be able to do it alone.

Ingrid Chastain readily agreed to accompany her father to deliver vaccines to a mining town in the Montana Territory. She never could have anticipated a terrible accident would leave her alone and badly injured in the wilderness. When rescue comes in the form of a mysterious mountain man who tends her injuries, she's hesitant to put her trust in this quiet man who seems to have his own wounds. 

Gray Delacroix has dedicated his life to building his very successful global spice empire, but it has come at a cost. Resolved to salvage his family before it spirals out of control, he returns to his ancestral home to save his brother and sister before it's too late. As a junior botanist for the Smithsonian, Annabelle Larkin has been charged with the impossible task of gaining access to the notoriously private Delacroix plant collection. If she fails, she will be out of a job and the family farm in Kansas will go under. 

Unflinching and plainspoken, Tessa Swan is not your typical 18th-century woman. Born and bred on the Western Virginia frontier along with her five brothers, she is a force to be reckoned with. Quiet and courageous, Clay Tygart is not your typical 18th-century man. Raised by Lenape Indians, he returns a hero from the French and Indian War to the fort that bears his name, bringing with him Tessa's long-lost friend, Keturah, a redeemed Indian captive like himself. Determined to avoid any romantic entanglements as fort commander, Clay remains aloof whenever he encounters the lovely Tessa.

Living in London's poorest slum, Mercy Wilkins has little hope of a better life. When she's offered an opportunity to join a bride ship sailing to British Columbia, she agrees. After witnessing so much painful heartache and loss in the slums, the bride ship is her only prospect to escape a bleak future, not only for herself but, she hopes, someday for her sister. Wealthy and titled Joseph Colville leaves home and takes to the sea - as ship's surgeon - in order to escape the pain of losing his family. When Mercy becomes his assistant, the two must fight against a forbidden love.