Chief Inspector Armand Gamache and his team investigate a series of perplexing murders, in the seemingly idyllic village of Three Pines and uncover the buried secrets of its eccentric residents. In the process, Gamache is forced to confront buried secrets of his own. Based on the novels by Louise Penny.

After losing her mom in an accident, a teen and her father welcome a distant cousin named Sienna into their household. Hoping to claim the family as her own, the psychopathic Sienna hatches a devious plan to recreate the prom she never experienced.