Based on author Herbie J Pilato's exclusive interviews with Elizabeth Montgomery prior to her death in 1995, Twitch Upon a Star includes insider material and commentary from several individuals associated with her remarkable life and career before, during, and after Bewitched, including her classic feature films The Court Martial of Billy Mitchell (1955), Who's Been Sleeping In My Bed? (1963), and Johnny Cool (1963).

Two of Montgomery's many popular TV movies, A Case of Rape (which remains one of the highest-rated TV movies of all time) and The Legend of Lizzie Borden, were groundbreaking and remain classics. But Twitch Upon a Star also goes behind the scenes to explore Montgomery's political activism, including her early advocacy for AIDS sufferers and the peace movement; her support for all minorities, including the gay community and the disabled; and her controversial participation as narrator of the 1988 feature film documentary Cover-Up and its 1991 Oscar-winning sequel, The Panama Deception. The book also explores Montgomery's tumultuous relationships with her father, screen legend Robert Montgomery (she was a liberal; he was a staunch conservative), and her four husbands. Through it all–and to family and friends–she was just Lizzie: down-to-earth and unaffected, just like Samantha, the "witch-with-a-twitch" Stephens, her most famous role.