Agent Liz Carlyle Series (abridged)

An announcement is made at a meeting of the British Intelligence Joint Counter-Terrorist group: "The opposition may be about to deploy an invisible." An "invisible" is CIA-speak for the ultimate intelligence nightmare: a terrorist who is an ethnic native of the target country and who can therefore cross its borders unchecked, move around the country unquestioned, and go unnoticed while setting up the foundation for monstrous harm.

MI5 Intelligence Officer Liz Carlyle learns from one of her agents that suspicious meetings have been taking place at an Islamic bookshop. She feels instinctively that a terrorist cell is at work and when she reports this to Charles Wetherby, the Director of Counter Terrorism, a surveillance operation is immediately put into place. An attack seems imminent.

Liz Carlyle, a smart, impassioned MI5 intelligence officer, has always been particularly skilled at "assessing people", and she trusts her instinct that a terrorist cell is at work at an Islamic bookshop. But when her boss, Charles Wetherby, suddenly takes her off the case, she's shocked to hear why: Wetherby has received a tip-off that a mole has been planted in one of the branches of British Intelligence.

Liz Carlyle has been transferred to Counter-Espionage, along with her research sidekick Peggy Kingsolving. Although the department has downsized since the end of the Cold War, there are still spies: including Russian spies who now keep an eye on the international financial community as well as the wealthy, influential Russian "oligarchs" in London. Liz is assigned to stop a Russian government plot to "silence" one of these oligarchs.