The discovery of a prosthetic arm in the river leads detectives to look into the case of a woman in the National Guard who went missing shortly after returning from a tour of duty in Iraq, where she lost an arm. Detectives learn she had trouble fitting back into civilian life.
A married couple were gunned down in their car during their weekly run for a take-out but their young autistic son riding in the back seat is spared. The parents also left behind a teenage daughter. The couple were owners of a local tropical fish store, there didn't seem to be any motive. As the only witness, their autistic son's ability to remember events with numerical sequence was always the same regarding his parents. Detective Valens showed a compassion and patience to learn to communicate with the autistic son's abilities that brought forth the clues to unravel ...
The team reopens a 1979 murder of a schoolteacher when new evidence, including a key-chain belonging to a man with whom the victim had been having an affair, turns up in the wooded area where the body was found. The investigation soon discovers that the relationship was not kept a secret from anyone, including both of the spouses and their children.
Bags of undelivered mail are discovered at the house of a mailman following his death. One of the undelivered items is a letter from an eight year old girl to her best friend, post-marked the day that she was abducted from her bedroom in 1975.