As the bus heaved down the road, bouncing at every pothole and piece of trash in the way, Jonathon Roberts suddenly realized he had never met the driver. The man that operated the vehicle Jon needed to survive the trip outside was an anonymous figure. The idea of entrusting his life to him was troubling.

Large metal flaps dropped quickly over the windows of the bus, darkening the inside completely for moment. Jon winced as the sickly white lights clicked on, casting a pallor on the interior.

Outside, objects banged against the hull of the vehicle. Sticks, stones, bullets: though he knew it was safe, Jon jumped at every sound. He always did. He heard stories about those sounds. People trapped outside the walls. Infected by the cloud.

The sounds died down and, soon, the metal flaps raised again. Sunlight, bleak and cold, flowed in once more. Jon’s breath steadied. He could see the walls coming closer. The dome field over the city. The clean air inside.

And the looming black cloud overhead.