Geneva, 2012. When a Russian intelligence officer approaches MI5 with vital information about the imminent cyber-sabotage of an Anglo-American Defence programme, he refuses to talk to anyone but Liz Carlyle. But who is he, and what is his connection to the British agent? At a tracking station in Nevada, US Navy officers watch in horror as one of their unmanned drones plummets out of the sky, and panic spreads through the British and American Intelligence services. Is this a Russian plot to disable the West's defences? Or is the threat coming from elsewhere? As Liz and her team hunt for a mole inside the MOD, the trail leads them from Geneva, to Marseilles and into a labyrinth of international intrigue, in a race against time to stop the Cold War heating up once again...

«For MI5 Intelligence Officer Liz Carlyle the nagging complications of her private life are quickly forgotten at Monday's Counter-Terrorist meeting. An invisible may have entered mainland Britain. An «invisible» — a terrorist who is an ethnic native of the target country, who can cross its borders unchecked and move about unnoticed — is the ultimate nightmare. For Liz this signals the start of an operation that will test her to the limit. Who or what is the target? Where and who is the invisible? With each passing hour the danger increases. But as she desperately sifts the incoming intelligence and analyses the reports from her agents she finally realises that it is her ability to get inside her enemy's head that is the only hope of averting disaster.»