Falling Darkness is the Halloween episode of Lewis.
Plot[]
Stem cell researcher Ligeia Willard is murdered with a stake through her heart on Hallowe'en; Dr Laura Hobson reveals that the victim is a former university friend of hers. More murders occur connected to Laura's past, and Lewis wonders whether the pathologist is holding something back. A medium, who claims to have foreseen the death, conducts a séance, but Lewis and Hathaway rely on more conventional methods to solve the murder.