by Diane J Cornwell
On their last boundary ride before winter, Dallas and Misty discover sick sheep. While Dallas and his tracker horse, Swift, use magic to heal the sick sheep, Misty and her tracker horse, Sweetie, help gather the rest of the flock.
At sunset, when Misty does not return Dallas and Swift search for her and the missing flock. He finds two dead slavers and an injured shepherd. The rest are missing.