With their mother, Eva (Chatarina Larsson), working late night shifts at a local hotel, 19-year-old Linus (Daniel Larsson) and his 17-year-old sister Vanja (Lina Englund) spend the majority of their time alone together in their home. Over the course of a month, the two siblings grow increasingly codependent and emotionally isolated from the outside world, excluding potential friends and romantic partners. Their intense emotional closeness gradually transitions into unspoken romantic longings and mutual physical attraction. Once their feelings are expressed, they cross into a secret incestuous sexual relationship, which inevitably forces them to confront intense shame, guilt, and the confrontation of their mother upon discovery.