Fresh from medical school in the 1860s--and a woman at that--the young Dr. Cheney Duvall struggles to find a position. She has almost given up hope when Asa Mercer turns up. He wants her services to chaperone and care for two hundred brides-to-be on a sea voyage from New York to Washington Territory. Cheney jumps at the opportunity. Accompanied by an unlikely nurse, Shiloh Irons, Cheney finds herself facing an arduous voyage and dangers for which her medical training didn't prepare her.