After the sudden death of their mother, the girls’ lives change forever. Lou reluctantly returns home from her high-powered job in New York to take over the business of the ranch. Amy realizes she’s inherited her mother’s special horse-whispering gift and is determined to keep her mother’s dream alive by maintaining Heartland as a horse rescue centre. Grandpa Jack just wants to keep the peace. This proves difficult when the girls estranged father returns to Heartland looking to reconnect with his daughters. Thrown into the mix is a new stable boy with a tragic past; a precocious 11-year-old girl next door who has an answer for every question; and the local vet who had a thing for Lou back in high school – and maybe still does.