Rellik is a serial killer story told backward. That explains the unusual title for the series, which is "Killer" spelled backward. While the killer will be revealed at the beginning, the thriller drama is said to offer a surprising take as it traces back the killer's story.
This series is based on an original idea by best-selling Danish novelist Elsebeth Egholm. It follows the inquiries of a special unit at Copenhagen's police force, consisting of detective inspector Katrina Ries Jensen (Laura Bach) and forensic psychiatrist Thomas Schaeffer (Jakob Cedergren). The pair specialise in serial killers that do not fit within traditional behavioural patterns.