O n a summer evening in 2007, 19-year-old student Carrie Symonds was waiting for a night bus after going out with friends on the King’s Road in Chelsea. A black cab pulled up, and its driver offered to take her home to East Sheen; he lived round there too, he claimed, and would accept just £5 for the fare. Once she was in the car, the driver told her that he’d just won big at the casino and invited her to raise a glass of champagne to celebrate. When he wasn’t looking, she poured it onto the floor, fearing it might be spiked. Later, he persuaded her to drink a shot of vodka; feeling indebted for the cheap cab ride, she agreed. From that point on, she couldn’t remember much, but according to her mum, she could barely walk when she arrived home. Months later, she would read about the case of John Worboys , the “black cab rapist” accused of drugging female passengers with spiked champagne then attacking them.…