Two fillies leave the safety of their family herd when they would rather swim in the pond than go with the herd to the morning dust bath that would keep them comfortable from biting insects. The fillies return to home range first to admire the herd talisman, "The Heart of the Mustang" necklace. The fillies take the talisman with them to the pond and discover it missing aft er their swim. With help from Smarty Owl, they search throughout the desert.
The herd finds them gone and they race off to find the fillies, only to be deterred by the "Wolf Brothers." Will the fillies find the talisman? Will the family herd find the missing fillies before sundown?