The main theme of Blackheart, by Mark Brazaitis, is the relationship between Emily, a girl and a guard dog in a vineyard near the city of Mendoza (Argentina), where she went to live for a while, since her mother's husband, called Ed, had to write about food and wine. When she thinks of Blackheart, she often compares him to her father.
In an interview, Mark Brazaitis, tells that Blackheart is based on the relationship of his youngest daughter with a guard dog in the vineyard where they lived in Argentina.