Nelly McDermott, the granddaughter of a prominent politician, loses her husband, architect Adam Cauliff, in a fiery boat explosion. When she's informed that he was murdered, Nell is compelled to find the killer by searching for the truth, with the help of a psychic, which could solve the mystery — or end her life.

Detectives Nick O'Malley and Kate Benson work in Special Unit 2, a secret precinct of the Chicago Police Department whose sole charge is to protect the city's citizens from Links, a malicious paranormal species that is the missing link between man and beast.