A silent, simmering killer terrorized New England in 1911. As a terrible heat wave killed more than 2,000 people, another silent killer began her own murderous spree. "Sister Amy" Archer-Gilligan, who'd opened the Archer Home for Elderly People and Chronic Invalids four years earlier, would be accused of murdering both of her husbands and up to sixty-six of her patients with cocktails of lemonade and arsenic; her story inspired the Broadway hit Arsenic and Old Lace. This is historical true crime at its best.