Cain His Brother

In her sixth William Monk mystery, Perry evokes early Victorian London with her usual skill, although the novel is somewhat hampered by an awkward plot element. Genevieve Stonefield comes to Monk for help, believing that her missing husband, the upright Angus Stonefield, has been murdered by his depraved twin brother, Caleb. When Monk finds evidence of Angus's death, he also comes upon a makeshift typhoid hospital staffed by his two friends, Lady Callandra Daviot and Hester Latterly. The relationship between Hester and Monk seems excessively turbulent this time out, marked by an antagonism that is unexpectedly harsh after the moments of closeness they shared in the previous book (The Sins of the Wolf). More interesting than the resolution of Angus's death is a subplot involving a woman from Monk's past whom the amnesiac investigator can't recall. The fate of their friendship and his investigation into her past make up the best parts of a story which, while written with care and intelligence, suffers from a predictable ending.(Oct.)