The Fortress Combatants

The world has been struck by a virus that turned humans into dangerous creatures. The government had built a huge ship, The Fortress, as a countermeasure. As humankind was pushed to the brink, they all tried to escape to The Fortress but not everyone was lucky enough to board. What awaits the few survivors in this nightmare? Will they be able to fight and reclaim their lands from this creatures? Or will they all sink with their hope?