The series begins six years after a virus spread through rain has wiped out most of Scandinavia's population. Simone and Rasmus Andersen, siblings who took refuge in a high-tech bunker, emerge to find a desolate world. They join a group of young survivors, embarking on a quest across Denmark and Sweden to find their father, a scientist who may hold the key to a cure. Along the way, they confront not only the dangers of the environment but also the complexities of human emotions, including love, jealousy, and the challenges of coming-of-age in a post-apocalyptic setting.

* **Simone Andersen**: The older sister, determined and protective. She leads the group in search of safety and answers, often acting as the moral compass.

* **Rasmus Andersen**: Simone’s brother, whose unique connection to the virus becomes central to the storyline.

* **Martin**: A former Apollon employee, resourceful and knowledgeable about the virus, making him a valuable ally to the siblings.

* **Patrick**: A member of Martin's group, skeptical and often challenges decisions, providing a contrasting perspective within the group.

* **Lea**: Compassionate and empathetic, forming a close bond with Simone and offering emotional support throughout their journey.

* **Jean**: Pragmatic and strong-willed, an essential member of the group who contributes to their survival strategies.

* **Beatrice**: Introduced in Season 1, a mysterious character whose past intertwines with the virus outbreak, adding complexity to the group dynamics.

* **Fie**: Introduced in Season 2, brings a different skill set and perspective, aiding the group in their quest for a cure.

* **Sarah**: Her relationship with Rasmus deepens in Season 2, and she plays a pivotal role in the unfolding events.

* **Kira**: Resilient and determined, joins the group in later seasons, bringing new insights and strength.

* **Sten**: A recurring character in Season 1, involved with Apollon, adding intrigue and tension to the storyline.

* **Daniel**: Introduced in Season 3, adds depth and new challenges for the group to face.