When college student Fumika stumbles upon the bullet that ended hitman Kudo's life, his vengeful spirit takes hold of her body. Now possessed by a ruthless assassin's rage and skills, she becomes an unstoppable force, hunting down those responsible for his death. As the body count rises, the line between Fumika and Kudo begins to blur. From the action director of Baby Assassins, One-Percent Warrior, and Bad City, Ghost Killer delivers a furious tale of supernatural revenge.

Librarian Miriam Gordon (Britt Lower) lives in a fog of grief while working amidst marginalized members of the public who populate the Allen Gardens branch of the Toronto Public Libraries. When a burgeoning love-affair with Janko, a younger foreign cab driver (Tom Mercier), coincides with her receiving a series of oddly threatening letters addressed to her, Miriam's sheltered existence is cracked open.

Based on the 2019 novel of the same name by Stephen King, the series stars Ben Barnes, Mary-Louise Parker and Joe Freeman in the main roles, and follows a young teenager who wakes up in a place where children possess special abilities, only to discover its institute's dark secrets.