In the grim darkness of the Warhammer 40k universe, a vat-born warrior awakens, floating in a vat of green liquid aboard a remote space station. With no knowledge of his origins, Azraelius embarks on a journey of self-discovery, learning that he is the product of an experiment to create the perfect being from the genetic material of an Astartes of the Thousand Sons Legion. As he explores the space station, Azraelius uncovers the knowledge and skills he needs to survive.