First-novelist Green introduces 30-ish nurse Kate Kinsella, whose ambition is to be a detective specializing in medical- background cases. Encouraged by her office landlord, Humbert Humberstone, who runs the funeral parlor on the ground floor of the building, Kate takes on her first client--the aunt of Jacky Byfield, a nurse stabbed to death while running an errand at seedy St. Dymphna's Hospital. Jacky was young, religious, and apparently led a blameless life, but Kate, who takes a job at St. Dymphna's in her search for leads, finds that Jacky had a small fortune in a London bank, and a lover--Mich O'Dowd, a security guard at the hospital. There are more murders and lots of artificially pumped-up suspense before a clumsy reconstruction of the killing leads Kate to a confrontation--awkward and unconvincing--with the killer. Despite its limp-along narrative and a clutch of downbeat characters (who take the edge off Kate's cheerfully amateurish efforts), there's talent here that may be better honed in future outings.