In the four years since her husband's death, midwife Sarah Brandt has become an angel of mercy in the tenements of turn-of-the-century New York, helping the less fortunate bring new life into the world -- and with Detective Sergeant Frank Malloy, seeing that justice is done for them.

Now, out of his affection for Sarah, Malloy has taken up the task of solving the murder of Dr. Tom Brandt, though the odds of finding reliable witnesses are slim. He learns that the good doctor was treating several dangerously delusional women, which leads him to a plausible suspicion. But when he discovers what he believes to be the truth, the shocking revelation may destroy Sarah, as well as any hopes Malloy ever had for a future with her . . .