In a world 10 years into the future, vampires make up the vast majority of the population with only 5% of the human race remaining. This presents particular challenges as the vampires' food supply - human blood - is dwindling and rationing is now the norm. Dr. Edward Dalton, a vampire and hematologist who works for a pharmaceutical firm, has been working on finding an artificial blood supply that will meet the vampire society's needs. He is sympathetic to humans and sees his work as a way of alleviating their suffering but his views on finding a solution change considerably when he meets someone who found a way to transform himself from being a vampire to again take human form.