A breathless “guess the twist” thriller written in an earnest, first person present style that irks the reader every few pages, “The Girl in the Mirror” arrives laden with its inciting premise. Iris and Claire are identical twins who separated in the womb just before birth; quite alike to strangers, inside body and mind they are completely unalike. And when Iris, sailing from Thailand to the Seychelles with Claire, finds herself alone on the boat, a classic identity ploy kicks off, one that involves trickery, inheritances, and double crosses. The twist and the double twist seemed to telegraph themselves to me (you might have a completely different experience), and the characters swirling around Iris were clearly props, but the author is adept at propelling and muddying the story. In the end, The Girl in the Mirror delivers on its promise: a serpentine plot unraveled at the speed of an evening’s sofa read.