The Other Wife

I enjoyed The Other Wife by Michael Robotham which is set in England.  Joe O'Loughlin is called to his father William's hospital bed to learn he has been seriously assaulted. By William's bedside is a woman Joe has never met before.  She claims to be William's "second wife".  Joe tries to discover what has happened.  Who has assaulted William?  Who is this woman with him?  Everything Joe thought he knew about his father comes into question as he tries to discover the truth. 4/5