In A Dark House by Deborah Crombie

In this novel in Deborah Crombie's excellent police investigation series, Duncan Kincaid has been called to the scene of a murder.  A woman's body has been found in a warehouse that burned the night before.  It is unclear if the murder was the reason the fire was set, or if it was a coincidence.  It also is unclear who the victim was.  There are several women missing, and any of them could fit the forensic description of the victim.

The warehouse's closest neighbor was a woman's shelter for victims of domestic abuse.  Was the victim Laura, who was on the shelter's board of directors?  She is missing, along with her ten year old daughter.  Did someone kill her and take her daughter, as her ex-husband believes, or did Laura decide to take her daughter and move to keep her from her father?  The daughter of the warehouse owner is missing, and a street camera shows her in the vicinity shortly before the fire.  Is she the victim?  A local woman who is sick and has a roommate to help out during her recuperation reports that the roommate is missing.  As the investigation into her disappearance evolves, it turns out that she wasn't what she proclaimed she was, having multiple identities and life stories depending on her audience.   Could that be the victim?

Then there are the fires.  Does this section of London have an arsonist at work?  If so, none of the usual clues to an arsonist seem to exist, such as multiple points of origin.  But as the fire investigators work, they start to see a cunning mind behind a series of recent fires that point to a very careful setting of fires, perhaps designed to prove the arsonist is better than the fire service and police can be. 

As Duncan works through the case, his former work partner, now domestic partner, Gemma James, gets involved.  When they became a family, Duncan and Gemma split into different teams, but their cases often require coordination between them.  In the meantime, life goes on with it's own issues.  Duncan and Gemma are facing a court case where their oldest son's grandparents are suing for custody.  Will they be able to convince a judge that their family, composed of children each of them brought to the partnership, is able to care for the children, or will the judge decide that their careers make them unfit to give the children enough care and attention? 

This is the tenth book in Crombie's Kincaid/James series.  It is satisfyingly complex, while showing the inside of a police investigation.  But Crombie's real strength is the human side of police work, showing how the crimes they investigate affect family's lives and how the policeman's own life can impact the work, or how the work can impact their lives.  This book is recommended for mystery lovers.