In Touch, North presents a rather creepier alternative: ''ghosts'' who can transfer their consciousness from body to body at will through the slightest touch of skin.
Such possessions are as long or as short as the whim of the ghost dictates and can last for moments, just enough time to misplace a wallet or drive around the block, or for so long that those possessed awake to find decades vanished in the blink of an eye.
The narrator, Kepler, has been a ghost for hundreds of years and has made a living at times as an ''estate agent'', finding suitable bodies for fellow ghosts to inhabit and providing essential little details - shoe size, favourite food, mother's maiden name - that they need to successfully step into their ready-made lives.
But unlike many of its kind, who desire nothing more than a succession of young, beautiful skins and who move on as soon as their host suffers injury or illness, Kepler has developed both an affection for the bodies it inhabits and an ethical approach to their use.
When possible it negotiates a price for occupation with a body's ''real'' owner before taking control, and tries to leave him or her better off on departure than when it found them.
It has also hired its services out to ordinary people, taking their own bodies into situations they are too scared to face themselves, or inhabiting somebody else's for a variety of reasons ranging from revenge to the rescue of a wayward daughter's reputation.
So when a man deliberately kills one of its hosts, despite knowing it is no longer in residence, Kepler takes it personally.
What follows is a cat-and mouse chase across eastern and central Europe between Kepler, its would-be assassins, and the mastermind behind the attack, a ghost called Galileo whose history is littered with the bodies of the hosts it has murdered and who nearly killed Kepler last time they met.
Touch is a complex and difficult novel to categorise and is much more than a mere thriller, delving as it does into larger philosophical questions about identity, morality and the psychological response to immortality.
It is also in its own strange way a romance.
Galileo's murderous rage is a response to an unfulfilled need for love, while Kepler's actions are driven for an equally voracious desire for humanity.
North (one of the pen-names of Catherine Webb) manages the delicate balance between fear and fascination brilliantly; her invisible protagonists tap into the same primal fear that make monsters such as Steven Moffat's Weeping Angels and The Silence so terrifying, but there is enough of the human in Kepler that the reader can readily empathise with its plight and care about its survival.
However, this is not a book for the faint-hearted and its basic premise still haunts me. Tell me, have you been losing time recently?
• Cushla McKinney is a Dunedin scientist.
