Is this love or just oxytocin? The brilliant second novel by the bestselling author of Things my Girlfriend and I Have Argued About

Tom Cartwright is a ghost-writer: eking out a living in Edinburgh, he is always ready to assumethe persona of a struggling working mother-of-four, or a round-the-world yachtsman, or a 'sensual' aromatherapist - indeed anyone his agent asks him to be, so long as it brings in money. When he is offered the highly lucrative task of ghosting the autobiography of glamorous young soap star Georgina Nye, he and his girlfriend Sara are thrilled: Sara is a big fan of George's and Tom will finally be able to afford some new carpets for their house.

But soon things go awry when Tom finds himself drawn to George by forces outside his control (even though they are inside his own body). Does his relationship with Sara stand a chance in the face of this explosion of chemistry? Is this love or just oxytocin - and is there a difference?