In the Grand Hotel in the centre of Stockholm a man is found brutally murdered. The previous evening he'd been tricked into buying dinner and paying for a room for a homeless woman. Sibylla has been homeless for fifteen years; so far as the authorities are concerned she doesn't exist and because of a history of mental illness she's an easy target for the police, particularly when there are further murders. She begins by running, hiding anywhere she can - and then she fights back to clear her name.