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.