Penelope Taberner Cameron is a solitary and a sickly child, a reader and a dreamer. Her mother, indeed, is of the opinion that the girl has grown all too attached to the products of her imagination and decides to send her away from London for a restorative dose of fresh country air. But staying at Thackers, in remote Derbyshire, Penelope is soon caught up in a new mystery, as she finds herself transported at unforeseeable intervals back and forth from modern to Elizabethan times. There she becomes part of a remarkable family that is, Penelope realizes, in terrible danger as they plot to free Mary, Queen of Scots, from the prison in which Queen Elizabeth has confined her.

Penelope knows the tragic end that awaits the Scottish queen, but she can neither change the course of events nor persuade her new family of the hopelessness of their cause, which love, loyalty, and justice all compel them to embrace. Caught between present and past, Penelope is ever more torn by questions of freedom and fate. To travel in time, she discovers, is to be very much alone. And yet the slow recurrent rhythms of the natural world, beautifully captured by Alison Uttley, also speak of a greater ongoing life that transcends the passage of the years.