2022: Detective Hildur Rúnarsdóttir returns from a surfing holiday in Hawaii to a good life. The renovation of her childhood home is progressing, and her colleague and friend Jakob Johanson has permanently joined her in Iceland. But when Hildur visits her family friend, Helga, in a nursing home, she is presented with surprising new details about her mother, Rakel. Then a cruise ship carrying a large group of tourists arrives in Ísafjörður, bringing a world of trouble with them.