Matilda Gray's mother commits suicide as she's about to tour New York. She finds items related to Carys Howell among her mum's possessions, a young girl who disappeared from a Welsh village twenty years ago. She decides to investigate the connection.

A series of encounters with the residents of Penllynith unsettle Matilda and she begins to suspect that Rose is hiding something, while a sinister air hangs over the events in Dean House.

Matilda fails to sway police with what she thinks is a clue to the disappearance of Carys, while Aron Morgan makes a formal complaint regarding Matilda's harassment of Davey. Trudy's part in the disappearance of Carys leaves her feeling guilty.

Matilda speaks with Laura, who claims she has crucial information about the disappearance of Carys, while Matilda experiences blackouts and Aron struggles with feelings of guilt and anger.

Laura warns Matilda that she's in grave and imminent danger, Kendrick agrees to do everything he can to reopen the case, Matilda considers who she can trust and Hal's romance helps him reflect.

Suffering from serious injuries, Sean manages to make it to Dean House to warn Matilda, she worries about Davey's safety and Trudy rues her harsh words as she pines for Hal.