Sweden faces a mysterious attack while Alex tries to reunite with his youth love, Anna.

Sara takes a job as a cleaner to find her missing daughter and strikes an uneasy alliance with the sinister janitor. They venture with a small group into the abyss underneath Malmö and the heart of darkness.

Caroline, a woman in her late thirties, has lost everything and is searching for a new beginning. She moves into an old apartment and starts to realize that she is not as alone as she thought she was. Just as she is searching for something new, something old is searching for her.