The Benevent Treasure (Miss Silver #26)

Invited to live with her two great-aunts, the Misses Cara and Olivia Benevent, Candida Sayle has no home of her own and accepts. But the offer takes on an eerie quality when the aunts recall the family legacy--the Benevent Treasure that brings death to all who touch it. When Candida becomes reacquainted with local architect Stephen Eversley, he worries for her safety and calls in Miss Silver. But she is already on the case, investigating the mysterious disappearance years earlier of a man sho worked for the sisters, and knew a bit too much, perhaps, about the Benevent Treasure.