Not being, in any sense of the word, science fiction, Red Hart Magic is not typical André Norton, though there are resemblances, both in theme and treatment, to a book she wrote in 1968 called Octagon Magic.

When teenagers Nan and Chris first meet they resent both each other and the recent marriage between their respective parents, both abroad. Through the agency of a model of the Red Hart Inn, near Rye, they move back in time to three separate adventures at the Inn, where they help one another, in the seventeenth, eighteenth and probably early nineteenth centuries. Interspersed are scenes at home and school, where they are severely tested by a dare to go shop lifting, bullying, and the attentions of a well meaning but rather insensitive aunt with whom they now live. The twentieth-century scenes are true to life but not fully alive; the three adventures in past time are excellent: they are fast-moving, fully involve the reader's imagination and sympathy, and are peopled with real adults, good and bad. (p. 60)

Norman Culpan, in The School Librarian, March, 1978.