Amid the ruins of a city shattered by a sudden cataclysm, a small group of survivors struggles to endure the early days of a mysterious viral epidemic. They take shelter inside a largely undamaged shopping mall, hoping its walls will shield them from the infected maniacs that roam the devastated streets outside. Inside the structure, however, tensions mount as madness and fresh threats emerge from every corner, leaving the group with nowhere safe to turn. Each decision grows more urgent as the boundaries between refuge and ruin steadily dissolve.