Helen Grace is investigating seemingly random and horrific crimes. Pairs of people are kidnapped and locked away with a gun, starving and dying of thirst until one shoots the other and is released. It is a story of unthinkable choices and the repercussions of those choices. Powerful psychological moments. As the pattern of victims is unveiled, Helen's past comes back with a bang. 
 This is a very thought-provoking, intense and emotional read.