National Park Service volunteer Roberta "Bert" Leneham has a plum assignment. She is to travel by boat to isolated Shackleford Island on North Carolina's Outer Banks. There, she will lend a hand in a roundup of the island's wild horses, which need to be counted and checked for disease. But her plans for an idyllic couple of days are quickly shattered. A foal turns up missing. It appears that equine infectious anemia may be present among the herd, and that veterinary records were altered to hide it. And then one of the volunteers is found dead in the dunes. There are those who believe the roundup worker was trampled by the most spirited, troublesome stallion on the island, a conclusion Bert refuses to accept. In the meantime, her deepening relationship with park ranger Hunter O'Hagan runs into trouble. Complicating matters is the rumored discovery of a turtle carcass on the beach, an event that would bring coastal dredging operations to a halt and cost millions of dollars in revenue. As Bert probes the volunteer's death, she hears the legends of the Shackleford herd-how the highly refined breed had its origins in North Africa, Spain, and Ireland before being transported through the Caribbean islands and shipwrecked off the North Carolina coast. Who is the person with the greatest stake in the herd's being certified as disease-free? The answer to that question will likely shed light on the killer. And how is that person connected to the moneyed interests that want the dredging to continue.