The Square by Celia Walden

Addison Square is one of the most desirable addresses in London. But behind the bright white facades, darkness lurks...Colette spends a lot of her time at Addison Square. She knows the place and the people better than anyone. But the wealthy residents she works for can barely remember her name. Which is unfortunate, because Colette knows all about them. She sees all their secrets. Even the ones they'd kill to protect.