Set in a ruined world after World War II, the series follows a small community of survivors hiding in a secret Swiss military base high in the Alps. In 1941, a German chemical experiment meant to create a powerful new weapon went catastrophically wrong, turning test subjects into violent undead creatures. Within months the infection spread across Europe, and within years the entire world collapsed. By 1947, civilization has fallen. High in the frozen mountains of Switzerland, around forty survivors struggle to stay alive in an isolated alpine fortress. Among them is Klaus Richter, a former German commander who deserted after witnessing the horrifying experiment that unleashed the outbreak. Haunted by guilt and distrust from others, he becomes the group’s main strategist, designing the traps and defenses that protect the base. Alongside him is Arthur Bennett, a British RAF pilot shot down over France during the early days of the catastrophe who fought his way across war-torn Europe to reach Switzerland. There is also Captain James Walker, a United States Navy officer whose fleet was destroyed during the collapse of civilization, leaving him stranded far from home. The group is anchored by three Swiss survivors who know the Alps better than anyone: Lukas Meier, a former Swiss mountain infantry soldier who leads patrols and scouting missions; Jonas Keller, a skilled alpine hunter who risks his life searching the mountains for food; and Dr. Elise Baumann, a determined doctor trying to understand the mysterious infection that destroyed the world. Keeping hope alive is Erik Vogel, a German radio operator who spends countless hours scanning the silent airwaves, searching for signs that humanity still survives somewhere beyond the mountains. Inside their hidden base, the survivors live under strict rules. Gunfire is used only as a last resort to avoid attracting the undead. Instead they rely on silent weapons, carefully placed traps, and explosives hidden around.