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? The appearance of a mysterious Polish girl adds fuel to the friction within the family.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. Written and created by Marietta KirkbrideCassie …… Kate O’Flynn Interviewer ….. Laurel Lefkow Morgan ..... Owain Gwynn Joyce ….. Kezrena James Bryn …… Macsen Ovens Huw …… Richard Corgan Ola …… Aggy K. AdamsOther voices played by the castProduction Manager: Anna de Wolff Evans Production Assistant: Teresa Milewski Executive Producer: Sara DaviesTitle Music: Ioana Selaru & Melo-Zed Sound Design: Jon NichollsDirected and Produced by Nicolas JacksonAn Afonica production for BBC Radio 4