Faber-Penguin Audiobooks, UK, no date.  ISBN 0-14-180330-4.  2 audio cassette tapes with an approximate playing time of 3 ¼ hours; still in manufacturer’s shrink wrap, original price sticker on rear.  Read by Sian Phillips.  “’What if my great-grandmother is a witch?’ thought Tolly.  Tolly’s great-grandmother wasn’t a witch, but both she and her old house, Green Knowe, were full of a very special kind of magic.  And Green Knowe turned out not to be the lonely place Tolly had imagined it to be.  There were other children living in the house – children who had been happy there centuries before.” (from rear case)