Linnea Newberry is brilliant scientist on the adventure of a lifetime, traveling along the Santa Fe Trail with her grandfather, Dr. Powell, on a botanical expedition to Colorado Territory. She wants to be taken seriously by the other team members, but with every calamity she faces, her grandfather threatens to send her home.
Flynn McQuaid watched his ma suffer and die in childbirth, so he's sworn off women and marriage forever. Heading west to embark on a new life, he has his hands full not only taking care of his younger siblings, but also delivering cattle to his brother. He doesn't need more complications.
As Flynn rescues Linnea from drowning during a river crossing, Dr. Powell quickly hires Flynn, unbeknownst to Linnea, to serve as her bodyguard for the remainder of the trip. As Flynn fights against the dangers of the trail, he soon finds himself in the greatest danger of all, falling for a woman he's determined not to love.