A pregnant mare, riding lessons, a horse show, and a cattle roundup prove challenging for all.
Amy and Lou take in an elderly neighbor's pony and Ty's old girlfriend from the juvenile group home shows up looking for him. Meanwhile, Mallory starts obsessing over Jack's health.
Prize-winning rider Nick Harwell stops by Heartland. Mallory discovers a crooked ranch-hand who plans to sell a herd of wild mustangs to a slaughterhouse.
A famous racehorse comes to Heartland for healing, which brings some unwanted media attention.
