The setting is a post apocalyptic world brought about by war between gods and their followers that only recently ended due to divine equivalents of nukes that wiped out most humans and gods. The story follows the travel of a man and his daughter as they make their way up north to a safe haven for surviving humans and gods. With nothing but their camping and survival supplies to help them keep on, they have to brave this lonesome world overrun by nature and spirits. Most are friendly enough not to pose as threats but there certainly are those that would bring them no good should they cross paths.
The pair come across such a threat and escape into a derelict temple hoping it would have enough divinity remaining to protect them. Unfortunately for them there would be no protection to be afforded to them by the building and the spirit digs its fangs into the girl. Seemingly satisfied with its misdeed, the spirit allows the two to say their farewells and takes its leave of them. The father pleads for her to hang in there and not to leave him alone but he has no means to actually save her.
That's when he hears a voice call out to him telling him that she can offer him more time with his daughter in exchange for a favor. He answers the voice saying he'll do anything to save his daughter and the voice declares that their pact is made. The daughter's body is enveloped by a faint glow and a spectral double of the girl rises out from corpse. The pair are surprised at the miracle and the voice makes itself apparent by taking control over the girl's astral form.
The voice introduces herself as the goddess housed by the temple and tells the father that she is in need of believers to maintain her existence. To accomplish that he needs to become a believer himself and bring her idol with him to a place that's still populated by living humans. So long as she has enough faith powering her, she'll be able to bind his daughter's spirit to him. His daughter will no longer be able to live on in the physical world but she can still stay by his side so long as he fulfills his end of the bargain.
Their pact is made and his destination remains the same but the stakes have risen dramatically as the goddess can only just barely maintain the daughter's astral body by possessing it. If he doesn't find more believers for her, she herself will eventually cease to exist along with his daughter. Now effectively making the journey alone, the father begins his trek to the distant promised land in the north.
The twist is that the goddess is the same spirit that killed the daughter was seriously desperate to secure at least a single believer.