Andi Carter has just turned nine. She and her palomino, Taffy, are old enough to be a real horse-and-rider pair at last! With a beautiful new saddle, Andi's sure she is ready to learn to trick ride like her friend Riley used to do before he left the ranch.

Sadly, big brother Chad knocks down any trick-riding plans, but Andi cheers up when she discovers a new friend at her special spot. Her fun with Sadie is soon threatened, though. They are caught in the middle of a boundary quarrel between the two families. Both Sadie's pa and Chad are stubborn as mules and neither will back down.