: DI Ravi Dhillon and DS Nick Holness investigate the brutal murder of Harold Slade. Their search leads them to a hotel room rented by a man named Gideon , where they find notes and photos linking to the Slade murder and an upcoming crime.
: Her eight-year-old son, Isaac , is emotionally unresponsive and detached. He speaks of imaginary friends and claims to see people in the house who aren't there. The Devil’s Hour 1x1
: A mysterious figure seen in a future timeline being interrogated by Lucy. He claims to understand her experiences and the nature of "the loop". : DI Ravi Dhillon and DS Nick Holness
: A social worker who experiences frequent déjà vu and visions of things that haven't happened. He speaks of imaginary friends and claims to
: Lucy consistently wakes up at exactly 3:33 AM following terrifying nightmares of a woman (her mother, Sylvia) contemplating suicide.
: Gideon’s walls feature names linked to these crimes, including Lucy Chambers , who was the caseworker for some of the victims. Key Characters