Here's the premise of this elegant, trippy travelogue: Girl, 30, in last gasp of adolescent fervour, temporarily shrugs off glittering career in journalism to jaunt round world with hubby in tow in search of the ultimate E. Her hightail off into hedonism takes Decca Aitkenhead, Guardian and Evening Standard columnist, to the drug dives of Detroit, the warehouse clubs of San Francisco, the beaches of Thailand, the townships of South Africa, etc, etc, etc.