Bloodguilt. Shadowless, #1

Nuclear fire brought endless night. The darkness hides invisible terrors known as entities. After the end of the world, Dr. Swaggart knows a demon has infected mankind's last shelter. He knows of a cure: but that means going down the mountain. In the dark. And with a damaged oxygen tank.--------------------------Sheltered in the underground Ark 1 facility, Earth's last 300 humans fear the dark above all else...
the shadows hide an ancient, primal evil--one that can take control of people, and which humans have no defense against. Deep within the miles of well lit corridors, the lights begin to flicker and fail. Before a new darkness falls, a drug addict and a man with Downs syndrome must reclaim the light and stop a new and final demonic Armageddon... but they learn that someone inside Ark 1 had more to do with unleashing these hellish fiends than any of the survivors know.
Stay in the Light... Stay alive. Get book 1 in this sci-fi thriller now!