Belle is a thirty-something woman obsessed with beauty routines. The first chapter of Rouge, Mona Awad’s fourth novel, opens with our protagonist hiding in the bathroom at her own mother’s wake, watching a video about skincare on her phone. By day, she works in a dress shop in Montreal (having grown up helping out at her mother’s boutique); by night, she’s mainlining serums, creams and unguents while scrolling through online videos by her favourite beauty influencer.  Belle is also, for the moment, back in California. She’s trying to make sense of her mother’s untimely death – the latter tumbled down the nearby cliffside in what’s being described as a freak accident – while dealing with the funeral arrangements and trying to wrap up the deceased’s estate. Soon, odd events lead her to the gates of the nearby La Maison de Méduse, a swanky but creepy spa that counted her mother among its patrons, and seems to promise beauty treatments like no other.…