As a farmer turned mercenary, Summer Glide lives her life one bullet at a time. After being hired by Bullet Gospel- a scientist working for a group calling themselves Servants of the Apocalypse- she's dragged on a journey to the faraway shores Greyscale island. After the ship that they hired wrecks upon its shores, their attempts to find a way home accidentally awakens the island's centuries old defenses. In turn, an even greater threat hiding within the mountain comes out to play. When these monsters of the Old World kidnap Bullet Gospel, it's up to Summer Glide to traverse the island, navigate the multitude of horrors it contains and get her back before they're both turned into instruments of war.