Interesting mystery set in Boston operating on a couple of levels. Forensic psychologist and expert on human memory Dr. Peter Zak becomes involved in helping a public defender defend a murder client. Surviving witness who was shot in the head, identifies a person who murdered of her boyfriend and shooting her in the head. Zak is called in the help determine whether witness's memory is really accurate. Zak is also still recovering from the murder of his wife a year previously and dealing with various psychological problems resulting from that.