Nadeem Aslam was years into his second novel when the 11 September attacks took place. "Many writers said the books they were writing were now worthless," he recalls. Martin Amis, for one, felt his work in progress had been reduced to a "pitiable babble". But Aslam's saddened reaction to 9/11 was one of recognition. "I thought, that's Maps for Lost Lovers – that's the book I'm writing."