A Civil War reenactment group has turned Blue Hill's park into a historic battlefield, but there's a battle of a different type brewing after a precious heirloom goes missing. Elderly sisters Nellie Brown and Betty Warring share a home and the biographies they regularly check out from the library, but when an antique dueling pistol awarded to their ancestor during the Civil War disappears, the siblings turn against each other. It's up to Anne to find out what happened to the valuable pistol and mend their relationship. Meanwhile, Anne, Ben, and Liddie befriend a family participating in the reenactment, but suspicions regarding the missing pistol might ruin their new friendship before it even begins.