She did know this much for certain: through that channel, MI6 had obtained the name of a city (Xiamen) and a couple of mobile numbers. Radio frequency devices had been used to scan for the digital signature of those mobile phones and slowly zero in on the place where they were being used. Much of this had been done in collaboration with American three-letter agencies, through pure signals intelligence technology: satellites, listening posts on the nearby Taiwanese island of Kinmen, and remote-control devices dropped in Xiamen by contract operatives who, of course, had no idea what they were doing or who they were working for.