The new novel from the No.1 Sunday Times bestselling author of Disclaimer.

She knows all your secrets. But will she keep them?

Look around you. Who holds the most power in the room? Is it the one who speaks loudest, who looks the part, who has the most money, who commands the most respect?

Or perhaps it's someone like Christine Butcher- a meek, overlooked figure, who silently bears witness as information is shared and secrets are whispered. Someone who quietly, perhaps even unwittingly, gathers together knowledge of the people she's there to serve - the ones who don't notice her, the ones who consider themselves to be important.

There's a fine line between loyalty and obsession. And when someone like Christine Butcher is pushed to her limit, she might just become the most dangerous person in the room . . .

The eagerly anticipated new thriller from the No.1 bestselling author of Disclaimer.