Checkmate Gettysburg

Over the last 35 years and 21 murders, a man we will call Scorpion decides to challenge Dolly Hamilton and Freestone to a battle of wits and gamesmanship. He sends Freestone to Gettysburg and other major Civil War battlefields to solve clues that will give them the names of his victims and where they are buried. The clock is ticking; however, because he plans to grab someone Dolly knows to prove he's the best. Can Freestone save the victim's life in time and catch the demented killer from Dolly's past?