Addy and Prue Fairweather live with Nell, their widowed mother, in a flat above her shop on the Scotland Road. The sisters, however, are very different. Addy is dark-haired, plain and always in trouble whereas Prue is flaxen-haired, blue-eyed and as angelic as her looks imply. To make matters worse, Nell makes no secret of her preference for the younger girl, increasing Addy's jealousy and resentment.

On the other side of the coin, Giles Frobisher and his twin sister, Gillian, live in a crumbling mansion near the sea in Devon. The family have lost most of their money in the Depression, so Giles leaves university and joins the Fleet Air Arm. He meets the Fairweather girls briefly on a visit to Liverpool but they lose touch. When they meet again Addy and Prue are no longer children and Giles realises he is falling in love ...