Amy discovers that a horse named Spartan is being abused at Mallen’s farm and convinces her mother Marion to rescue him. A storm on the way home sends their truck and trailer off the road. When Amy wakes up, she’s in the hospital and discovers that her mother died in the accident. Amy’s sister Lou comes home from New York to help. Refusing to put Spartan down, Grandpa Jack brings the horse back to Heartland hoping that Amy can help him. Before Amy can help Spartan, she has to come to terms with what happened to her mom. A boy named Ty who was hired by Marion before she died comes to work at Heartland. He is on probation, and Amy immediately dislikes him.

Lou sends home Mrs. Roach's horse, despite the fact that his fear of vehicles has yet to be cured. Val Stanton begins spreading rumors about Heartland and their skills without Marion. Ty's probation officer comes to the ranch while he is off showing Amy the jumping course he made for her. Jack agrees to be Ty's sponsor in the place of Marion, his deceased daughter.

Heartland has its first Open House and Lou invites their estranged dad Tim and he accepts the invitation. Amy works with world famous horse breeder Lisa Stillman's horse, Promise. Jack kicks Tim off of the property. Marion's horse Pegasus is depressed because of Marion's death.

When Amy and Lou empty their mother’s room, they find a letter dated seven years earlier from their father. A new guy, Ben, is sent to Heartland by his aunt, Lisa Stillman, and nobody likes him, especially Ty, who gets really angry when he pushes his horse too far. Amy gets knocked off her horse while trying to take Ben’s horse across the river. Ty is offered a job at Briar Ridge even after Amy accidentally tells Ashley that Ty is on probation. When Amy hears that Ty might take the job, she snaps at him.

Lou drives friends and family to distraction as she arranges to have a video made to promote Heartland.

Lou's New York boyfriend Carl comes for a visit, but his big city plans clash with the ranch's more laid-back lifestyle. Amy is puzzled by why a new horse at Heartland called Pirate won't obey commands.