 According to Stross, in 2001, he had already sold two books to the publisher Ace Books, "Singularity Sky" and "Iron Sunrise".Ace also had the right of first refusal to any future science fiction books Stross would publish, and would likely only publish one book of his a year so as not to have his books compete against themselves.His agent advised him that if he wished to sell more books without breach of contract and also to avoid self-cannibalization, he should branch out genres, and encouraged Stross to try his hand at a fantasy series.