Emma (Kaley Cuoco) and Dave (David Oyelowo) spice up their wedding anniversary with a night of role-play in New York City. But things turn perilous when Emma's secret life as an international assassin, unknown to Dave, is exposed by Bob (Bill Nighy), jeopardizing her family. Emma must rely on her lethal skills and determination to protect her family at all costs.

The members of the Demon Slayer Corps are plunged into an otherworldly realm for their climactic final battle against Muzan Kibutsuji.