When Swallows Fall — Gloria Davidson Marlow

Although Ophelia Garrett loved Cade Scott first, it was her sister he married and took home to his plantation. When Ophelia receives word of her sister's murder and Cade's arrest, she travels there on a mission to learn the truth. She soon finds the halls of Almenara are haunted by secrets, peril, and quite possibly her sister's ghost.
Despite the cold, angry man Cade has become, Ophelia's heart refuses to believe he is a murderer. Vowing to do everything she can to prove his innocence, Ophelia must open wounds she'd hoped were long healed and face the feelings that still burn between her and Cade. As everyone looks to Cade as the suspect, evil haunts the dunes and halls of Almenara, bringing death to two more young women and forcing Ophelia to confront the danger.