John le Carré's The Circus: Losing Control #1

Every day, behind closed doors, the men and women of The Circus are embroiled in high stakes, high-wire acts that the average citizen would never notice. These intelligence officers protect Britain's most sensitive secrets. At the head of it all is Control: an all-powerful puppet master who decides who goes where, who does what, and sometimes, if necessary, who lives and who dies. But now, Control has vanished.

He doesn't show up at the office. He misses his meetings. He won't—or can't—answer his phone. He is simply nowhere. Control's assistant Maggie is the only one who knows he's gone, and with a mole's identity blown in Moscow, the clock is ticking. A member of "The Mothers" – the unsung fleet of assistants and secretaries who hold the show together behind the scenes of The Circus – Maggie knows every protocol, every password, and every operative—but she has no idea whether something has happened to Control or whether this is part of his plan. Either way, she can't trust anyone. No-one can know Control is missing. And can she even trust Control? Secrets within The Circus have a way of unravelling, and Maggie will have to act fast… or risk the walls tumbling down around her.