In 1875 California, Brody MacKenzie arrives at the Two Harts Ranch on a mission to find his runaway brothers, worried they may have fallen into harm. Instead, he discovers them thriving at the ranch's school and orphanage under the care of Ellie Hart, a woman with a heart as resilient as the land she calls home. His options limited, Brody reluctantly takes on the role of ranch doctor, and he forms an unexpected bond with Ellie, who's kept a steady eye on Brody's two rapscallion brothers. When the boys show him a mysterious journal that has been guiding their travels and may hold the key to a lost treasure, Brody and Ellie are captivated by the possibility of a thrilling adventure.

With winter approaching and his brothers threatening to bolt again, Brody and Ellie race against time to decipher cryptic clues and unearth the hidden fortune. But along the way, old adversaries resurface, threatening their newfound affection and the safety of those at the ranch.