Episode description

A psychological horror story set in rural Wales amid the mysterious world of mycelium.

When social worker Cassie discovers mould in the flat of a vulnerable service user she puts it down to poor quality housing. But then she discovers it in her own house and begins to fear for the safety of her family.

For partner Morgan and young son Bryn, it’s not the mould that troubles them but Cassie’s mental health. As the fungus continues to grow and spread, Cassie resorts to more extreme measures to combat it. But why will no one listen to her when she warns of danger? In Greek mythology, Cassandra was condemned to speak the truth yet never be believed.

A story of trust and what happens when we lose it. And of a hidden threat attacking the very thing that makes us powerful.