Lila Emerson is fascinated by other people's lives. As a house-sitter, she loves looking after the glamorous, sophisticated homes she could never afford herself. And as a writer, she enjoys watching the world go by, dreaming up stories for the people she sees from her window.

But then one day she witnesses something only too real - the brutal and shocking murder of a young woman living across the street in New York. And now, because of what she saw, Lila's own life is in immediate danger from an audacious, single-minded assassin who kills for profit and for pleasure.

With the police following a false lead, Lila is on her own. Her only hope is to team up with Ashley Archer, an artist with his own complicated reasons for getting involved. Lila wants to trust the passionate, quick-witted Ash - but is she letting her feelings blind her to his motives? Either way, Lila will never watch from the sidelines again...