It's been four months since Ty's sudden and unexplained departure, and Amy has moved on and become used to working with Caleb Odell, Heartland's new stable hand. With Amy's 16th birthday just days away, Lou is busy planning a surprise birthday party for her sister.
When Ty comes back to Heartland, he quickly realizes that profound changes have occurred in his absence. Caleb, the new ranch hand, seems to have taken over both his job and his place in Amy's heart.
When Tim gives Amy a beautiful Grand Prix jumper for her birthday, she's forced to make a difficult choice between a career in show jumping and her work at Heartland.
The spring cattle drive is a much-anticipated event, and Lou hustles everyone out of the house at the crack of dawn for a secret all-day date with Scott. Simmering tensions rise to the surface as Amy seems more interested in getting roping tips from Caleb instead of riding with Ty.
Lou is forced to reconsider her choice to live and work at Heartland when her former New York colleagues arrive for a weekend equine retreat. Amy is unsure whether she can trust Ty.
Out for a ride along the river, Amy comes across an RCMP officer desperately trying to save a young boy from drowning. Scott misinterprets Nick Harwell's polo match invitation to Lou as a date. Mallory seeks Jack's advice on how to deal with her love life.
With the annual Hudson Heritage Rodeo looming, everyone at Heartland gets roped into the action. Jack and Tim are forced to work together on the planning committee. Meanwhile, Lou is grooming Soraya to compete in the Queen of The Rodeo competition.
In the middle of a heat wave, a cattle truck loaded with thirsty and overheated horses pulls into Heartland. Ty can hardly believe his eyes when the driver turns out to be his dad.
Ty asks Amy to give their relationship another chance. Ashley makes a decision that surprises her mother and Lou. Cattle rustlers hit Big River Ranch, and the situation gets out of hand.
When Amy's teacher brings a horse named Boxer to Heartland, Amy learns a valuable lesson about fathers and daughters. Ty and Kit seem to be blissfully happy together. Lou catches Constable Rodriguez with another woman.
When Hollywood comes to Heartland, Amy is so starstruck, she loses track of what's really important in her life.
Lisa meddles in Lou's business and personal life with disastrous results. Lisa brings a "cursed" horse for Amy to treat. The beautiful Andalusian named Diva Girl has been returned to Lisa by multiple owners.
Lou goes head to head with Big Alberta Oil when seismic surveyors force their way onto Heartland.
Ty's former probation officer, Clint, brings two troubled youths to Heartland forcing Ty to revisit his troubled past. Meanwhile, one of the two youths forms a surprising friendship with Mallory.
Lou resurrects the Hudson Derby, stirring up an age-old grudge match between Jack and Tim.
Amy resorts to desperate measures when her horse Spartan is mysteriously stolen and reappears sold to Wes, the man who set fire to the Heartland barn.
Amy heads into the mountains to visit a First Nations horse healer named Victor Whitetail, and leaves with a new understanding about horses, her mom and herself.
Ty and Amy confront their feelings for each other after bringing hay up to Jack's fishing cabin. The trip becomes complicated when Ty becomes sick and a snowstorm strands the two of them at the cabin. Meanwhile, Lou finally brings Peter home to meet Jack while Val tells Ashley about Val's sponsorship deal with Caleb.