Alicia has been a good wife to her husband, a former state attorney. After a very humiliating sex and corruption scandal, he is behind bars. She must now provide for her family and returns to work as a litigator in a law firm.
Det. Supt. Peter Boyd (played by Trevor Eve) is the leader of a multi-discipline police team of detectives and scientists, the Cold Case Squad, which investigates old, unsolved murder cases using modern methods and new technology that may not have been available during the original investigation.
After a serial killer imitates the plots of his novels, successful mystery novelist Richard "Rick" Castle gets permission from the Mayor of New York City to tag along with an NYPD homicide investigation team for research purposes.