To recreate the early 20th century killing spree which took place primarily in Connecticut's ""Archer Home for Elderly People and Chronic Invalids"" (the inspiration for Joseph Kesselring's play Arsenic and Old Lace), Phelps amasses an abundance of research to complement his already-extant authority on female murderers (the author of Perfect Poison: A Female Serial Killer's Deadly Medicine, Phelps has also consulted on serial killer TV drama Dexter). A seemingly charming setting, the Archer Home was run by Amy Archer-Gilligan, a homely ""Christian woman"" who provided the last hope of a comfortable home for many of her elderly residents. As a nasty heat wave overtook the East Coast, however, the number of deaths occurring in the Archer Home spiked precipitously. After 24 deaths over four years, a vigilant reporter noted that Archer-Gilligan has been purchasing large quantities of arsenic; she was using it to kill the very residents she'd sent to purchase it for her. Phelps' diligent research creates a vivid portrait of the country a century ago, but his telling is oddly dispassionate; readers may not fully understand the brutality of Archer-Gilligan's crimes until the list of the dead at end of the book, laid out over three full pages.