Lucan has been orphaned and Zosine has been deserted, and London is a hostile place for two young girls without a home.Bound together by poverty, grief and their shared years at school, they set out to make a future for themselves in new surroundings.They are adopted by the austere, puritanical Reverend Pennhallow and his wife, and in their large, gloomy house they become immersed in study.But, after a chain of disturbing events, it does not take long before they realize that the cleric and his wife are not all they seem to be ...