Ty and Scott Cardinal must survive in the wilderness, at the site of their plane crash, and try to make contact with their rescuers. The other residents of Heartland are not willing to sit around waiting so they load up their horses and head to the area where the plane disappeared to help with the search.
After the plane crash Ty is having nightmares and is unable to sleep. Jack, Tim and Ty head off for a weekend fishing trip and Lou's boyfriend Peter decides to accompany them. Lou is trying to prepare Heartland for a visit by a magazine photographer but is beset by a series of disasters and misses Peter. Mallory is hurt when her friend Jamie breaks their plans to hang out because Jamie wants to spend time with Rachel, the most popular girl in school.
As the second anniversary of Marion's death approaches, Victor comes to the ranch to pay his respects. As Tim begins to suspect that Victor and Marion's relationship was more than he thought, Jack and the girls are caught in the middle. Ty asks Amy to work with Kit's horse who's temperamental after losing a foal. Peter asks Lou to accompany him on a business trip Paris.
Kit Bailey's barrel racing horse Daisy has not been performing well since losing her foal. Ty encourages Kit to bring Daisy to Heartland to be treated by Amy, causing friction among them. When Daisy turns out to have Strangles Heartland is placed under quarantine and Pegasus's health is threatened. Meanwhile Amy is also dealing with a demanding client who is having problems with her dressage horse.
After getting a clean bill of health from her doctor Val Stanton is eager to enjoy life. She renews her interest in show jumping and hires Amy to coach her. Mallory is jealous when it appears Jake has a new girlfriend.
Amy and Ty find Mr. Hanley's horses wandering along the road. When they return them to the Hanley ranch it appears to be abandoned. Lou is invited to WWAHH, an organization of working women started by her friend Marnie, where she meets a lawyer, Caroline Hanley. Noticing the connection, Amy convinces Caroline to help her brother, Mr. Hanley, save his ranch.
With business still off at Heartland Tim and Lou pressure Amy to enter a horse breaking contest for publicity. Mallory is interested in joining her school riding club and seeks help from Amy and Caleb.
Lou and Peter must get married quickly because Peter needs to move to Dubai. Caleb is desperate to repair his relationship with Ashley. Amy has been invited to go on the Ring of Fire tour and Ty is feeling restless, wanting to set out on his own before beginning university.
Lou is in Dubai. Caleb & Ashley are on the circuit, and Amy has just returned from the Ring of Fire tour and Jack is glad that folks are coming home as the ranch is too much for him by himself. Then, Amy is disappointed that Ty's homecoming doesn't go as planned when he shows up with a female "friend" on the back of his motorcycle.
Nick Harwell is having trouble with his polo pony and Amy, Scott and Ty get involved. But will Nick's wealthy patron allow Nick to follow their advice? Meanwhile Lou is home for a visit. She's upset that the dude ranch has been neglected and Dubai may not be all that she thought it would be.
Mrs. Bell has an accident in her pony cart and Ty needs to treat Sugarfoot at Heartland. Lou has extended her stay at the ranch and is ducking calls from Peter who's still in Dubai. Chase shows up at the ranch and wants Amy to do a clinic with him. Ashley wants to host a birthday dinner for her Mother despite Caleb's misgivings.
As graduation looms, change comes to Heartland. Amy is offered a full scholarship at a university in Colorado. To Mallory's chagrin, Badger comes to work as a hand at the ranch. Lou and Tim arrange a deal to sell the dude ranch to Lisa. After several pointed suggestions from her mother, Ashley thinks about her future life with Caleb.
Peter returns from Dubai to find out what's going on with Lou. Sarah "Crazy" Craven's old horse is not well and Sarah brings it to Heartland. Mallory and Badger go back to the Craven place to feed the other animals but end up getting trapped there.
When Tim decides not to enter his horse in the big race, Janice his jockey/girl-friend agrees to ride for a competitor. Badger buys a car but finds out that its stolen and has to get rid of it before Jack finds out. When Soroya starts managing the dude ranch, Ashley wants to be promoted to manager at the café.
When Caleb needs some cash for a down-payment on his trailer lot he enters a team roping event. Amy is upset when he asks Kit to be his roping partner. Meanwhile Badger is trying to interpret the mixed signals he's getting from Mallory about their relationship status. Tim considers selling Lightning Dexter, his race horse, rather than keeping it through its convalescence period.
Amy is hired to teach a class of convicts about horse training as part of their work program. Ty is surprised when one of the cons turns out to be an old friend. Meanwhile Badger's summer at the ranch is coming to an end and he's upset that Mallory might just be using him in an effort to gain Jake's attention.
Lou comes back from Dubai to spend time with the family. Ty and Amy discover where her father's rustled cattle are being pastured and the whole family rides out to bring them back. Meanwhile Ashley's mother offers to give Ashley the lot that the trailer is on if she'll get Caleb to sign a marriage contract (pre-nup)