The appointment of Delia Davies, young, pretty and intelligent, to be headmistress of William Llewellyn school for girls causes raised eyebrows in turn-of-the-century Merioneth. Bitterly opposed to the new appointment is the evil Miss Kingston; and Captain Owen Rhys, a gentleman of independent mind and means, has his own reasons for hoping the new arrival's stay will be a short one.

As factions develop within the staff and community, Delia prepares to do battle to save her reputation and career.