Simo (Eppu Pastinen) and Jonna (Krista Hannula) are a young couple deeply in love. Their lives are upended when they uncover hints that Simo's mother and Jonna's father had an affair years ago. Faced with the horrifying possibility that they might actually be half-siblings, innocent suspicions unleash a chaotic chain reaction within their families as paranoia, manipulation, and dark family secrets come to light.