She's in your house. She controls your life. Now she's going to destroy it. A terrifying and timely new psychological thriller, from the No. 1 Sunday Times bestselling author of The Ice Twins. She watches you constantly.Newly divorced Jo is delighted to move into her best friend's spare room free of charge. The high-tech luxury Camden flat is managed by a meticulous Home Assistant. She takes care of the heating, the lights – and sometimes Jo even turns to her for company. She knows all your secrets.Until, late one night, the Home Assistant says one sentence that tears Jo's fragile world in two: 'I know what you did.' And Jo is horrified. Because in her past she did do something terrible. Something unforgivable. Now she wants to destroy you.Only two other people in the whole world know Jo's secret. And they would never tell anyone. Would they? As a winter blizzard brings London to a standstill, Jo begins to understand that the Home Assistant doesn't just want to control Jo's...