Two brothers who haven't spoken in years discover there are a great many things they don't know about each other in this dark drama. Luc (Jaap Spijkers) and his wife Mieke (Camilla Siegertsz) live in the Netherlands, where they were born and raised. Fifteen years before, Luc's brother Ad (Jack Wouterse) mysteriously disappeared, and no one has heard from him since, but one day Luc gets a surprising phone call informing him that Ad is alive and well and living in Belgium. Luc and Mieke quickly travel to Belgium to see Ad, though Mieke has some misgivings, since she's pregnant and due to give birth in a matter of weeks. Luc and Mieke discover than Ad and his wife Els (Renee Soutendijk) live in a tiny cottage in the woods, cut off from the world, and Ad has no particular interest in explaining what he's been doing for the fast decade and a half. Frustrated and wary of Ad and Els' shabby living conditions, Mieke soon returns home, but Luc stays on, hoping to rebuild his bridges with his brother. Time seems to only aggravate long-standing tensions between the brothers, which is not eased by the increasing rapport between Luc and Els. Before long, Luc begins hearing strange noises in the basement under Ad's hovel, and he discovers that Ad and Els have been hiding a terrible secret -- a deformed, almost feral boy who is kept in a cage like a wild animal.