When Amy discovers that a horse named Spartan is being abused at Mallen's farm, she convinces her mother Marion to rescue the horse and bring him back to Heartland. On the way home a raging storm sends their truck and horse trailer careening off the side of the road. When Amy wakes up in the hospital, she's forced to deal with the tragic news that her mother is dead.

Heartland's future is put in jeopardy when Lou mistakenly sends Mrs. Roche's horse, Swallow, home before his fear of traffic is fully cured. An unknowing Ashley rides Swallow and is violently thrown off when the horse is spooked by a truck.

In order to drum up business for Heartland, Lou is organizing an open house. Amy is totally against it. After all, she's managed to drum up some high profile clients on her own. Clients like Lisa Stillman, a well-known horse breeder who entrusts Amy with Promise, a very valuable horse who refuses to be saddled. But there's no way Lou can cancel, especially since she's secretly invited their father, Tim, to the open house to see Amy for the first time in ten years.

Impressed by Amy's work with Promise, Lisa Stillman sends her nephew Ben to live at Heartland. While Amy and Lou are cleaning out Marion's old room in preparation for Ben's arrival, they come across a letter written years ago by Tim asking for their mother's forgiveness. Marion had painted quite a different picture of Tim and the two sisters begin to see their father in a new light.

When Lou decides to make a promotional video to advertise Heartland, nobody is very supportive of the idea. But Lou is determined, perhaps even more than usual. She manages to recruit everyone at Heartland to spruce up the ranch, including Mallory and Ben who are assigned the messy task of moving the manure pile.

Lou's New York boyfriend, Carl, decides to pay Heartland a visit. The question on everyone's mind is how long is he staying? Carl has just been offered a lucrative position at a firm in Chicago and he has come to Heartland to convince Lou to go with him.