Tonio makes a disturbing discovery at the shore. Another harrowing night with Emma pushes Camille to her limit. Marianne turns up the heat.

Emma's grieving is cut short by an urgent request, and a grisly scene at the Daugeron home leads Inspector Ronan into a world of demonic secrets.

Fifteen years earlier, in a bid to drive away Emma’s nightmares, the friends gather at their old school for a ritual that will change their lives.

Inspector Ronan connects the dots between Emma's books and more real-world tragedies. He, Emma and Séby hatch a plan to destroy Marianne.

Fleeing to different parts of the island, the friends encounter terrifying sights and ghostly messengers. One by one, they turn on Emma.

As the priest makes a desperate bid to banish Marianne, Emma finds herself torn between two worlds, and Aurore searches for a way to save her friend.