Driving home late one night, Etain Larkin finds a corpse on a pitch-black country road deep in the Irish countryside. She takes the corpse to a remote farmhouse. So begins a night of unspeakable horror that will take her to the very brink of sanity.

She will never speak of it again.

Two decades later, Betty Fitzpatrick, newly arrived at college in Dublin, has already fallen in love with the drama society, and the beautiful but troubled Ashling Mallen. As their relationship blossoms, Ashling goes to great lengths to keep Betty away from her family, especially her alcoholic mother, Etain.

Gradually, Betty learns her lover's terrifying family history, and Ashling's secret obsession. Ashling has become convinced that the horrors inflicted on her family are connected to a seemingly innocent children's TV show. Everyone in Ireland watched this show in their youth, but Ash soon discovers that no one remembers it quite the same way. And only Ashling seems to remember its star: a small black goat puppet who lives in a box and only comes out if you don't behave. They say he's never come out.

Almost never.

When the door between the known and unknown opens, it can never close again.