TORONTO - It can be a tricky thing when authors fall in love with characters that don't have a home.
But when your first book proved to be an irresistible sci-fi love story about a time traveller, you figure out a way to breathe life into them.
Even if they're dead.
"'Her Fearful Symmetry' started out being about this man who can't leave his flat and a girl who comes and visits him," Audrey Niffenegger says, describing the early incarnation of her supernatural new novel.
After she decided the girl would have a twin, the author of "The Time Traveler's Wife" had a vague notion that she wanted the action to take place near a cemetery. Settling on London's famed Highgate, which opened in 1839, Niffenegger realized she needed a way to explain how her two female leads could afford such plum digs.
"The way the ghost got into it is the girls needed some reason that they had this astonishingly expensive flat," she says matter-of-factly. "That flat, in that location, if it existed, would be millions.
"There's no way a couple of 21-year-olds would be living in it; they couldn't even afford the rent. So I thought, 'They need someone to die and give them this flat.' Then I started to get interested in who this relative was and I started to like her so I said, 'She can be a ghost; that way I can write about her.'"
And as a lifelong fan of ghost stories, dipping her pen into the paranormal world was easy for her to do. Ouija boards and ghostly possession also fit nicely with her creative process.
"I'm easily bored and I'm constantly trying to evolve and change. I knew I wasn't going to write the 'Time Traveler's Daughter.' The difficult bit was figuring out how to get the open space where I didn't know what I was doing.
"But I love ghost stories," the Chicago-based writer continues, enthusiastically name-checking Henry James's "Turn of the Screw" as one of her favourites. And her background as a visual artist was enough to convince her she could have fun with the genre.
"There seems to be things that are always true of ghosts," she says. "Ghosts are cold, ghosts are hungry, ghosts want things they can't have. And they long to be alive again."
Content to adhere to those few rules, Niffenegger also let her ghost venture into dark human recesses, becoming a metaphor for jealousy, possessiveness and the taboos we invoke to live our lives.
"I know ghosts would like to influence things, but one of the most important qualities, according to me, is the longer they go being dead, the less compassion and empathy they have. They lose this quintessential human characteristic."
So the recently-deceased Elspeth Noblin, a self-absorbed woman not quite ready to let go of living, doesn't all of a sudden start to embody newfound generosity after she wills her American nieces a fancy new pad in a building full of artful eccentrics
"Elspeth is not exactly the most generous person when she's alive," she says, unapologetically describing the supporting star that tickled her heart. "And as she goes on being a ghost, she becomes more and more monstrous."
"Symmetry's" chilling ending isn't where Niffeneger envisioned concluding. After all, the book did start out chronicling a crossword maker too afraid to leave his home.
"But I always knew I'd arrive someplace different," she says. "Certainly there are the common themes between 'Time Traveler' and this.
"There's this theme of time passing and loss and death and the tension between loving somebody and knowing that time is going to eventually rip you apart. But with every project, especially these long ones, you don't know where you're going to end up.
"I don't know if you have to say, 'I'm not going to repeat myself,' because by the time you move through the process of doing it, you'll end up someplace else."
