Twin Killing is based on the lives of twin brothers, Ricky and Randy Brennan. Ricky is a lifelong manic-depressive, who has been unable to cope with his illness. Randy has generally been blessed with extraordinary good fortune throughout his years. In his 59th year, Randy learns that he has a few months to live. He has been diagnosed with a rare, incurable brain disorder. Twin Killing begins with an introduction to Martha, the twin's mother. In her teens, Martha becomes involved with the high school star athlete and heir to a successful candy manufacturer. A pregnancy, marriage, and birth of a girl follows. After two months, Martha witnesses the first "twin killing" as her baby is brutally killed by her drunken husband, followed by his arrest and suicide. Later, Martha gives birth to Ricky and Randy, in 1942 in Springfield, Massachusetts. Ricky Brennan is hospitalized after a tragic auto accident in 1964. Over the next 38 years a number of bizarre events occur, particularly while Ricky is in one of his manic cycles.
Approximately ten million Americans of all ages are diagnosed with bipolar disorder. The circumstances and end chosen by Ricky and Randy is unique and thought provoking.