This series set in New York around 1900-1910 is so entertaining. This particular book was well-plotted, with a very unexpected twist. Having read several of the later installments, it's interesting to have taken a step back in the relationship between lead characters Sarah Brandt, a society woman turned midwife, and Frank Malloy, a New York City detective. At that time, graft and payoffs to the police were rampant, and Frank would have been one of the few honest cops, though he certainly knew how it all worked.
Someday I'll go back to the beginning and read all the books in the series I've missed, which is still most of them, so I have plenty of enjoyment ahead.