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.

Scott invites Lou to a black tie dinner on the same night as the local high school's semi-formal. Ty accompanies Amy to the local dance leaving Jack home alone to mind the ranch. When an arsonist strikes, Jack is injured and can't recall exactly what happened. Will his memory recover in time to identify the culprit?