Icelandic sisters Áróra and Ísafold live in different countries and aren't on speaking terms, but when their mother loses contact with Ísafold, Áróra reluctantly returns to Iceland to find her sister. But she soon realizes that her sister isn't avoiding her … she has disappeared, without trace.

As she confronts Ísafold's abusive, drug-dealing boyfriend Björn, and begins to probe her sister's reclusive neighbours – who have their own reasons for staying out of sight – Áróra is led into an ever-darker web of intrigue and manipulation.

Baffled by the conflicting details of her sister's life, and blinded by the shiveringly bright midnight sun of the Icelandic summer, Áróra enlists the help of police officer Daníel, as she tries to track her sister's movements, and begins to tail Björn – but she isn't the only one watching…