1666 takes place during the great fire of London. Felicity Cutler is a 14 year old girl who performs tricks in taverns. When she wakes in the middle of the night at her home on Pudding Lane, her father’s gone and there’s a dead body in the cellar - the dead body has a coded clue on a chain around his neck. Flick must race through the city to solve the clues, while London burns around her.