I like the way in which information is naturally disseminated in the flow of history, in a suggested and not explicit way. I can guess that the price requested by the Moloch is the sacrifice of children, like many mythological monsters, like the Minotaur, and that Elli is pregnant and the couple does not want to give in to the blackmail of the monster.

He had resisted, feigned, redirected, but three months ago, she had come to him, her hand resting on her stomach, and he saw it.

I think, perhaps mistakenly, that this is the description of the moment when he discovered that Elli was expecting a baby.

P.S. the fantastic / science fiction details are pure gold