Julian Symons is mystery fiction's grand old man. Novelist, historian of the genre and student of true crime as well, he has brought all three passions together in his most recent novels: "The Blackheath Poisonings," "Sweet Adelaide" and now "The Detling Secret."

All three are set in Victorian England, a period and place that are to connoisseurs of crime what catnip is to a kitten. And with good reason…. Jack the Ripper excepted, it is the Victorian era's domestic murderers and their homely weapons (arsenic soaked from flypaper, ground glass in the gruel) that fascinate.

Mr. Symons' "Sweet Adelaide" was based on the case of Adelaide Bartlett, a Pimlico housewife who in 1896 was reluctantly acquitted of force-feeding chloroform to her husband. The members of the Detling family, though imaginary, seem equally based in reality. Surely more than one upper-class Victorian family consisted of a thickheaded baronet, a misleadingly...