Ten years ago, a brutal bacterial invasion wiped out most of the population of Scandinavia, and a young brother and sister began a journey to find a safe place. The only guide for the brother and sister is their father's diary, which records the dangers of bacteria and the new world. They join other young survivors and begin a dangerous journey across the border. Faced with a deadly disaster, the gang must quickly realize that the greatest danger does not come from the outside, but from within.