When Lucy Brennan, a Miami Beach personal-fitness trainer, disarms a gunman chasing two frightened homeless men, the police and the breaking-news cameras are not far behind and, within hours, Lucy is a media hero. The solitary eye-witness is the depressed and overweight Lena Sorensen, who becomes obsessed with Lucy and signs up as her client – though she seems more interested in the trainer’s body than her own. When the two women find themselves more closely aligned, and can’t stop thinking about the sex lives of Siamese twins, the real problems start… Superficially Lucy and Lena couldn’t really be more different. Lucy is toned and trim with a sharp tongue and an extrovert nature. Her foul mouth and gung-ho attitude towards life seems like the perfect tools to navigate life in the self-obsessed environment of Miami Beach. Lena meanwhile is the polar opposite. Overweight, introspective and shy she hides away from the world. Where Lucy appears confident and strong, Lena is weak willed and easily lead. A chance meeting brings the two together and it’s not long before they both realise that appearances can be more than a little deceptive. I love the way that Welsh’s characters often verge on…