It is 1718 and, in a small parish near Newcastle, Eliza Tally, a headstrong girl of 15, embarks on a reckless love affair that will prove her undoing. When her lover casts her off, denying their union, she is forced to travel to London, a city that attracts and alarms her in equal measure. There she takes up a position in the house of an apothecary, Grayson Black, whom she trusts to salvage what remains of her reputation.