Nick Harwell arrives to train Ben but becomes interested in buying Spartan. Mallory thinks Lou plans to re-home Copper and runs away with him, only to discover a plot to sell wild mustangs.

Disaster strikes when the barn erupts into flames and Jack's badly hurt getting the horses to safety.

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.