Still reeling from the loss of her boyfriend in a botched anti-terrorist operation, Liz Carlyle has been posted to MI5's counter-espionage desk, where she's hoping to have relative security to find her feet. However, Russia's incursions into the Crimea and President Putin's determination to silence those who oppose him, wherever they may be, quash that hope. Liz soon finds herself on the hunt for a Russian spy in Britain. And with MI5 and MI6 under painful public scrutiny in the post-Edward Snowden world, security seems like a remote possibility for Liz's team. --