Nursing as life-support and nursing as life-substitute are the intermingled themes of this straightforward collection of related narratives that seem to be memoirs written by a young English novelist who has studied nursing and midwifery in London. In the title story, a nurse working the ""Indefinite Nights"" of agency assignments avoids a former patient who has unexpectedly escaped death. When the youth was helpless, she was tender; but when she spots him in a library later just after losing her lover, she hides. ""He was a man again,"" she sees, ""able. . .to ask of me everything I knew I would never give him, not him, not anyone."" A similar avoidance of involvement in the birth and death intimacies of the hospital is echoed in ""The Quality of Mercy,"" which is set in the men's ward of ""Twenty-seven strangers, all old: the easiest people in the world to please."" She sticks to the job because ""I wanted to be needed, I wanted to be recognized."" Prostitutes sold sex, but ""it was nurses who sold love."" Although she accepts, in a story called ""The Products of Conception,"" a doctor's invitation for ""a drink"" after he has concluded one of a long series of abortions, he--like the husbands or lovers in Ferguson's other stories--seems more of a stereotype than a convincing or seductive figure. What counts in these ruminative ""case studies"" is that the narrator, who in one story is deserted by her father during childhood, finds substitute satisfactions at the hospitals. The wards provide: ""Strong entertainment, for us to try our nerves on, or impress our friends with."" The diagnosis--poignantly articulated but never resolved--is that: ""If you're not used to being grown-up yet, if you're shy, nursing can make a good substitute: you don't need to go out and make things happen to you. . .