A suspicious drowning of an elderly political agitator takes place in Victorian Canterbury's filthy river Stour.Private detective Esther Salomon is sent by the Metropolitan Police to help the Canterbury constabulary quietly investigate the suspected murder.

She finds a city wracked by cholera and typhoid, where everything seems connected to the 'Canterbury Stink' caused by the polluted river. To bring the killer to justice, she enlists the assistance of two other city visitors, the philosopher Karl Marx and the ex-burlesque actress and now sensation novelist Amy Price. But they are both also hiding their own secrets.